golfscript, 15 bytes

Result

WA

Duration

881ms

Code [DL]

8/{..2=?2*=}%n+

stdin

782 828
498 961
641 141
233 442
819 483
513 167
711 115
514 643
855 535
733 735
733 934
254 321
815 554
858 853
144 436
466 318
144 442
874 743
793 691
321 223
932 935
247 716
525 551
633 763
525 387
422 559
386 446
363 771
487 758
836 334
436 469
839 853

stdout

89134116533358464762975352437348

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffdef3cf6b0 /* 9 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x559819630d70 /* 9 vars */ <unfinished ...>
12    execve("/usr/local/ruby-2.7.1/bin/ruby", ["/usr/local/ruby-2.7.1/bin/ruby", "/root/golfscript.rb", "/volume/CODE"], 0x559819719028 /* 9 vars */ <unfinished ...>
11    <... execve resumed>)             = 0
12    <... execve resumed>)             = 0
11    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=11, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
12    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=4, si_stime=3} ---
10    +++ exited with 0 +++