fish-shell-pure, 101 bytes

Result

AC

Duration

1397ms

Code [DL]

while read -n1 _
read -n1 b
read -n1 c
read -n1 _
read -n1 d
read _
[ $b = $c ]&&echo $b||echo $d
end

stdin

123 772
171 488
433 339
554 247
667 154
133 992
848 441
889 766
865 558
344 883
448 342
578 283
233 273
822 763
183 332
573 376
224 245
844 451
192 275
845 991
233 434
388 869
116 114
776 472
781 146
758 626
545 546
766 364
682 831
216 122
377 773
753 534

stdout

7
4
3
2
1
3
4
7
5
4
3
2
3
2
3
3
2
4
2
9
3
8
1
4
1
6
5
6
8
1
7
5

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffe98299520 /* 9 vars */) = 0
11    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x55b2fd9e7d18 /* 9 vars */) = 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    execve("/bin/cp", ["cp", "-f", "/volume/CODE", "/opt/jails/fish-shell-pure/code."...], 0x55b2fd9e7d68 /* 9 vars */) = 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=0, si_stime=0} ---
14    execve("/usr/sbin/jk_chrootlaunch", ["jk_chrootlaunch", "-j", "/opt/jails/fish-shell-pure", "-x", "/bin/fish", "/code.fish"], 0x55b2febcd1b0 /* 9 vars */) = 0
13    execve("/bin/cat", ["cat", "-"], 0x55b2febcd0e0 /* 9 vars */) = 0
13    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
14    execve("/bin/fish", ["/bin/fish", "/code.fish"], 0x7ffe6c0bdff0 /* 9 vars */) = 0
14    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=0, si_utime=1, si_stime=1} ---
15    execve("/bin/rm", ["rm", "/opt/jails/fish-shell-pure/code."...], 0x55b2fd9e7cc8 /* 9 vars */) = 0
15    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=15, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
10    +++ exited with 0 +++