6.61/6.63 c MPhaseSAT version 401 by Jingchao Chen, April 1, 2011
6.61/6.63 c input CNF file=HOME/instance-3445835-1306983170.cnf
6.61/6.63 c Clause#=6174 var#=880 ratio=7
6.61/6.63 c phase 1
6.61/6.63 c verified
6.61/6.63 c
6.61/6.63 s SATISFIABLE
6.61/6.63 v -1 2 -3 4 5 6 -7 -8 -9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 22 23 -24 -25 26 -27 28 -29 30 -31 32 -33 34 -35 -36 -37 38 39 40 -41 42 -43 -44 45 46 -47 48 49 -50 -51 -52 -53 -54 55 56 -57 -58 -59 -60 61 -62 63 64 65 -66 -67 -68 69 -70 71 -72 -73 -74 75 -76 77 -78 79 80 81 82 83 -84 85 -86 -87 -88 89 -90 -91 92 93 94 95 -96 -97 98 99 100 -101 102 103 -104 -105 -106 -107 -108 -109 -110 -111 112 113 114 -115 -116 117 118 -119 -120 -121 122 123 124 -125 126 127 128 129 130 -131 132 133 -134 135 136 137 -138 139 140 141 142 -143 144 -145 146 -147 148 149 -150 151 -152 -153 -154 155 156 -157 -158 159 160 161 -162 163 -164 -165 166 167 168 -169 170 171 -172 -173 -174 -175 -176 -177 178 -179 -180 181 -182 -183 184 185 -186 -187 188 -189 190 -191 -192 193 -194 -195 -196 -197 198 199 -200 201 202 203 204 -205 -206 207 -208 -209 210 -211 -212 213 214 -215 -216 217 -218 -219 220 -221 -222 -223 -224 225 -226 227 228 229 -230 231 -232 233 -234 235 236 -237 238 -239 -240 241 -242 -243 244 -245 -246 247 248 -249 -250 -251 -252 -253 -254 -255 -256 -257 -258 259 260 261 262 263 -264 -265 266 267 -268 269 270 271 -272 -273 274 275 276 -277 278 279 -280 -281 -282 283 -284 -285 286 -287 288 -289 -290 -291 -292 293 -294 295 -296 297 -298 299 -300 301 302 -303 304 -305 306 307 308 -309 310 -311 312 313 -314 315 -316 -317 318 -319 -320 321 322 -323 -324 -325 326 327 -328 -329 -330 331 -332 -333 334 -335 336 -337 338 339 -340 -341 342 -343 -344 345 346 -347 -348 349 -350 -351 352 -353 -354 -355 -356 357 -358 359 -360 -361 362 -363 -364 -365 366 367 368 369 -370 371 -372 -373 374 -375 376 -377 -378 -379 380 -381 382 -383 -384 -385 -386 -387 388 389 390 391 -392 393 -394 -395 -396 397 398 399 400 401 -402 403 -404 -405 406 -407 408 409 -410 -411 412 -413 414 -415 416 417 418 419 -420 -421 -422 423 -424 -425 426 427 -428 429 430 431 -432 -433 -434 435 436 -437 -438 439 -440 441 -442 443 -444 445 446 -447 -448 -449 450 451 452 453 -454 -455 -456 457 458 459 460 461 -462 463 464 -465 -466 467 468 469 -470 471 472 473 -474 -475 476 477 -478 479 -480 -481 482 483 484 485 -486 487 -488 489 490 491 492 493 -494 -495 -496 -497 -498 499 -500 -501 502 503 504 -505 506 507 -508 509 510 -511 512 -513 514 515 516 517 -518 519 -520 521 -522 523 -524 -525 -526 527 528 529 -530 -531 532 533 -534 535 536 537 -538 539 540 -541 -542 -543 544 545 -546 547 -548 549 -550 -551 -552 -553 -554 -555 556 557 -558 -559 560 561 562 563 564 -565 566 -567 -568 569 570 571 -572 573 574 -575 -576 577 -578 579 -580 -581 -582 -583 -584 -585 -586 -587 -588 -589 590 591 -592 593 -594 595 -596 -597 -598 599 600 -601 -602 603 -604 605 606 607 -608 609 610 611 612 -613 614 -615 -616 617 618 -619 -620 621 -622 623 624 625 626 -627 -628 -629 630 631 -632 -633 634 -635 -636 637 -638 -639 -640 641 -642 -643 -644 645 646 647 -648 649 650 -651 652 -653 654 655 656 -657 -658 659 -660 661 -662 663 664 -665 666 -667 668 -669 670 671 672 673 -674 675 -676 677 678 -679 -680 681 -682 -683 -684 -685 686 687 688 689 690 691 692 693 694 695 696 697 -698 -699 700 -701 702 703 704 705 706 -707 708 -709 -710 711 -712 -713 -714 -715 716 717 -718 719 -720 721 722 723 -724 -725 -726 -727 728 -729 730 731 732 -733 -734 735 736 737 -738 739 740 -741 -742 -743 -744 -745 746 -747 -748 -749 750 751 -752 -753 -754 755 -756 757 758 -759 760 -761 -762 763 764 765 766 -767 768 -769 -770 -771 -772 773 774 775 776 -777 778 -779 780 -781 -782 -783 784 -785 -786 787 788 -789 790 -791 -792 -793 -794 -795 796 797 798 799 800 801 802 803 804 -805 806 -807 -808 -809 810 -811 -812 -813 814 -815 816 817 818 -819 820 -821 -822 823 824 825 826 -827 -828 829 -830 -831 832 -833 -834 835 836 -837 -838 839 840 841 -842 843 -844 845 846 847 -848 849 850 -851 852 853 854 -855 856 -857 858 -859 860 -861 -862 863 864 865 866 -867 -868 -869 870 -871 872 873 -874 -875 876 877 878 -879 880
6.61/6.63 v 0
6.61/6.63 c
6.61/6.63 c Running time=6.630992
runsolver Copyright (C) 2010-2011 Olivier ROUSSEL
This is runsolver version 3.3.0 (svn: 977)
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
command line: BIN/runsolver --timestamp -w /tmp/evaluation-result-3445835-1306983170/watcher-3445835-1306983170 -o /tmp/evaluation-result-3445835-1306983170/solver-3445835-1306983170 -C 5000 -W 5100 -M 15500 MPhaseSAT HOME/instance-3445835-1306983170.cnf
running on 4 cores: 1,3,5,7
Enforcing CPUTime limit (soft limit, will send SIGTERM then SIGKILL): 5000 seconds
Enforcing CPUTime limit (hard limit, will send SIGXCPU): 5030 seconds
Enforcing wall clock limit (soft limit, will send SIGTERM then SIGKILL): 5100 seconds
Enforcing VSIZE limit (soft limit, will send SIGTERM then SIGKILL): 15872000 KiB
Enforcing VSIZE limit (hard limit, stack expansion will fail with SIGSEGV, brk() and mmap() will return ENOMEM): 15923200 KiB
Current StackSize limit: 10240 KiB
[startup+0 s]
/proc/loadavg: 1.04 1.52 1.80 2/477 13616
/proc/meminfo: memFree=21629676/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=3432 CPUtime=0.01 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 477 0 0 0 1 0 0 0 25 0 1 0 790732358 3514368 407 33554432000 134512640 134731564 4288826544 18446744073709551615 9586172 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 858 408 250 54 0 168 0
[startup+0.097664 s]
/proc/loadavg: 1.04 1.52 1.80 2/477 13616
/proc/meminfo: memFree=21629676/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=4088 CPUtime=0.09 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 631 0 0 0 9 0 0 0 25 0 1 0 790732358 4186112 561 33554432000 134512640 134731564 4288826544 18446744073709551615 134715365 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1022 561 265 54 0 332 0
Current children cumulated CPU time (s) 0.09
Current children cumulated vsize (KiB) 4088
[startup+0.100664 s]
/proc/loadavg: 1.04 1.52 1.80 2/477 13616
/proc/meminfo: memFree=21629676/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=4088 CPUtime=0.09 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 631 0 0 0 9 0 0 0 25 0 1 0 790732358 4186112 561 33554432000 134512640 134731564 4288826544 18446744073709551615 134720309 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1022 561 265 54 0 332 0
Current children cumulated CPU time (s) 0.09
Current children cumulated vsize (KiB) 4088
[startup+0.300641 s]
/proc/loadavg: 1.04 1.52 1.80 2/477 13616
/proc/meminfo: memFree=21629676/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=4216 CPUtime=0.29 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 688 0 0 0 29 0 0 0 25 0 1 0 790732358 4317184 618 33554432000 134512640 134731564 4288826544 18446744073709551615 9326278 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1054 618 265 54 0 364 0
Current children cumulated CPU time (s) 0.29
Current children cumulated vsize (KiB) 4216
[startup+0.700558 s]
/proc/loadavg: 1.04 1.52 1.80 2/477 13616
/proc/meminfo: memFree=21629676/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=4472 CPUtime=0.69 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 735 0 0 0 69 0 0 0 25 0 1 0 790732358 4579328 665 33554432000 134512640 134731564 4288826544 18446744073709551615 134723198 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1118 665 265 54 0 428 0
Current children cumulated CPU time (s) 0.69
Current children cumulated vsize (KiB) 4472
[startup+1.50042 s]
/proc/loadavg: 1.04 1.52 1.80 3/478 13617
/proc/meminfo: memFree=21626844/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=4728 CPUtime=1.49 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 795 0 0 0 149 0 0 0 25 0 1 0 790732358 4841472 724 33554432000 134512640 134731564 4288826544 18446744073709551615 134721171 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1182 724 271 54 0 492 0
Current children cumulated CPU time (s) 1.49
Current children cumulated vsize (KiB) 4728
[startup+3.10013 s]
/proc/loadavg: 1.04 1.52 1.80 3/478 13617
/proc/meminfo: memFree=21624240/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=4984 CPUtime=3.09 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 876 0 0 0 309 0 0 0 25 0 1 0 790732358 5103616 805 33554432000 134512640 134731564 4288826544 18446744073709551615 134620725 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1246 805 271 54 0 556 0
Current children cumulated CPU time (s) 3.09
Current children cumulated vsize (KiB) 4984
[startup+6.30057 s]
/proc/loadavg: 1.11 1.53 1.80 3/478 13618
/proc/meminfo: memFree=21624884/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=5500 CPUtime=6.29 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 995 0 0 0 629 0 0 0 25 0 1 0 790732358 5632000 924 33554432000 134512640 134731564 4288826544 18446744073709551615 134620664 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1375 924 271 54 0 685 0
Current children cumulated CPU time (s) 6.29
Current children cumulated vsize (KiB) 5500
Solver just ended. Dumping a history of the last processes samples
[startup+6.50053 s]
/proc/loadavg: 1.11 1.53 1.80 3/478 13618
/proc/meminfo: memFree=21624528/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=5500 CPUtime=6.5 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 1009 0 0 0 650 0 0 0 25 0 1 0 790732358 5632000 938 33554432000 134512640 134731564 4288826544 18446744073709551615 134720151 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1375 938 271 54 0 685 0
Current children cumulated CPU time (s) 6.5
Current children cumulated vsize (KiB) 5500
[startup+6.61751 s]
/proc/loadavg: 1.11 1.53 1.80 3/478 13618
/proc/meminfo: memFree=21624528/32951124 swapFree=67057928/67111528
[pid=13616] ppid=13614 vsize=5500 CPUtime=6.61 cores=1,3,5,7
/proc/13616/stat : 13616 (MPhaseSAT) R 13614 13616 12297 0 -1 4202496 1012 0 0 0 661 0 0 0 25 0 1 0 790732358 5632000 941 33554432000 134512640 134731564 4288826544 18446744073709551615 134668845 0 0 4096 1026 0 0 0 17 5 0 0 0
/proc/13616/statm: 1375 941 271 54 0 685 0
Current children cumulated CPU time (s) 6.61
Current children cumulated vsize (KiB) 5500
Child status: 10
Real time (s): 6.63337
CPU time (s): 6.63199
CPU user time (s): 6.62699
CPU system time (s): 0.004999
CPU usage (%): 99.9793
Max. virtual memory (cumulated for all children) (KiB): 5500
getrusage(RUSAGE_CHILDREN,...) data:
user time used= 6.62699
system time used= 0.004999
maximum resident set size= 0
integral shared memory size= 0
integral unshared data size= 0
integral unshared stack size= 0
page reclaims= 1046
page faults= 0
swaps= 0
block input operations= 0
block output operations= 0
messages sent= 0
messages received= 0
signals received= 0
voluntary context switches= 7
involuntary context switches= 7
runsolver used 0.025996 second user time and 0.087986 second system time
The end
Begin job on node140 at 2011-06-02 04:52:50
IDJOB=3445835
IDBENCH=84580
IDSOLVER=1941
FILE ID=node140/3445835-1306983170
RUNJOBID= node140-1306983162-13543
PBS_JOBID= 13497672
Free space on /tmp= 73552 MiB
SOLVER NAME= MPhaseSAT 2011-02-15
BENCH NAME= SAT04/handmade/anton/l4k4/lksat-n900-m6174-k4-l4-s819398222.used-as.sat04-929.cnf
COMMAND LINE= MPhaseSAT BENCHNAME
RUNSOLVER COMMAND LINE= BIN/runsolver --timestamp -w /tmp/evaluation-result-3445835-1306983170/watcher-3445835-1306983170 -o /tmp/evaluation-result-3445835-1306983170/solver-3445835-1306983170 -C 5000 -W 5100 -M 15500 MPhaseSAT HOME/instance-3445835-1306983170.cnf
TIME LIMIT= 5000 seconds
MEMORY LIMIT= 15500 MiB
NBCORE= 4
MD5SUM BENCH= 82170fa4021e7a6c932a31c197f0f64c
RANDOM SEED=2084841757
node140.alineos.net Linux 2.6.18-164.el5 #1 SMP Thu Sep 3 03:28:30 EDT 2009
/proc/cpuinfo:
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5333.66
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 1
siblings : 4
core id : 0
cpu cores : 4
apicid : 16
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5226.14
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 2
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 1
cpu cores : 4
apicid : 2
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5332.75
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 3
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 1
siblings : 4
core id : 1
cpu cores : 4
apicid : 18
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5332.77
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 4
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 2
cpu cores : 4
apicid : 4
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5332.75
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 5
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 1
siblings : 4
core id : 2
cpu cores : 4
apicid : 20
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5332.74
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 6
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 0
siblings : 4
core id : 3
cpu cores : 4
apicid : 6
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5332.75
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
processor : 7
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU X5550 @ 2.67GHz
stepping : 5
cpu MHz : 2666.833
cache size : 8192 KB
physical id : 1
siblings : 4
core id : 3
cpu cores : 4
apicid : 22
fpu : yes
fpu_exception : yes
cpuid level : 11
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips : 5332.75
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: [8]
/proc/meminfo:
MemTotal: 32951124 kB
MemFree: 21629956 kB
Buffers: 260364 kB
Cached: 3800604 kB
SwapCached: 6932 kB
Active: 7237444 kB
Inactive: 3749424 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 32951124 kB
LowFree: 21629956 kB
SwapTotal: 67111528 kB
SwapFree: 67057928 kB
Dirty: 2084 kB
Writeback: 0 kB
AnonPages: 6924004 kB
Mapped: 39320 kB
Slab: 214128 kB
PageTables: 51936 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
CommitLimit: 83587088 kB
Committed_AS: 141411304 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 296008 kB
VmallocChunk: 34359440975 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
Hugepagesize: 2048 kB
Free space on /tmp at the end= 73552 MiB
End job on node140 at 2011-06-02 04:52:57