bash-pure, 88 bytes

Result

AC

Duration

885ms

Code [DL]

while read l;do
if [ ${l:1:1} = ${l:2:2} ];then
echo ${l:1:1}
else echo ${l:4:1}
fi
done

stdin

474 446
985 837
521 216
744 798
454 462
244 998
344 472
746 448
653 641
858 248
536 833
611 715
535 356
156 856
722 915
983 886
236 673
844 445
877 378
544 419
935 669
645 756
846 648
245 484
916 617
581 417
522 228
734 447
671 864
144 664
659 116
957 594

stdout

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

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffe646254b0 /* 9 vars */) = 0
12    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x56237e25ad18 /* 9 vars */) = 0
12    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
13    execve("/bin/cp", ["cp", "-f", "/volume/CODE", "/opt/jails/bash-pure/code.bash"], 0x56237e25ad58 /* 9 vars */) = 0
13    +++ exited with 0 +++
11    --- 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/cat", ["cat", "-"], 0x56237f6400d8 /* 9 vars */) = 0
15    execve("/usr/sbin/jk_chrootlaunch", ["jk_chrootlaunch", "-j", "/opt/jails/bash-pure", "-x", "/bin/bash", "/code.bash"], 0x56237f6401c0 /* 9 vars */) = 0
14    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
15    execve("/bin/bash", ["/bin/bash", "/code.bash"], 0x7fffb1528e10 /* 9 vars */) = 0
15    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=15, si_uid=0, si_status=0, si_utime=0, si_stime=1} ---
16    execve("/bin/rm", ["rm", "/opt/jails/bash-pure/code.bash"], 0x56237e25acb8 /* 9 vars */) = 0
16    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=16, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
11    +++ exited with 0 +++