vlang, 85 bytes

Result

WA

Duration

1190ms

Code [DL]

import os
fn main(){for a.len>0 {a:=os.get_line()
print(a[if a[1]==a[2]{2}else{4}])}}

stdin

887 753
817 494
161 369
389 988
944 117
161 651
737 174
274 772
686 422
488 883
542 293
244 445
942 798
621 215
635 559
635 351
255 537
514 442
186 385
954 647
744 559
493 887
494 894
884 886
914 991
122 127
844 438
855 278
867 765
744 253
395 936
899 492

stdout

stderr

/tmp/code.v:2:15: error: undefined: `a` 
    1| import os
    2| fn main(){for a.len>0 {a:=os.get_line()
                     ^
    3| print(a[if a[1]==a[2]{2}else{4}])}}

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7fff6f8b4610 /* 7 vars */) = 0
12    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x55fe79e02d18 /* 7 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", "/tmp/code.v"], 0x55fe79e02d38 /* 7 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", "-"], 0x55fe79e02d58 /* 7 vars */) = 0
15    execve("/root/v", ["/root/v", "run", "/tmp/code.v"], 0x55fe79e02d80 /* 7 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    +++ exited with 1 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=15, si_uid=0, si_status=1, si_utime=3, si_stime=3} ---
11    +++ exited with 1 +++