reasonml, 173 bytes

Result

WA

Duration

990ms

Code [DL]

for (i in 0 to 31) {
  let a = input_line(stdin);
  if (a.[1] == a.[2]) {
    print_endline(String.sub(a, 2, 2));
  } else {
    print_endline(String.sub(a, 4, 4));
  };
};

stdin

688 887
388 484
633 443
271 187
551 292
226 929
367 658
841 812
163 339
413 336
416 128
855 877
169 913
382 829
329 597
563 885
814 143
351 551
832 531
599 923
266 699
718 384
629 927
711 119
232 354
918 674
399 448
232 338
924 558
344 375
266 266
269 965

stdout

stderr

  Warning number 35
  /tmp/code.re 1:1-8:1
  
  1 │ for (i in 0 to 31) {
  2 │   let a = input_line(stdin);
  . │ ...
  7 │   };
  8 │ };
  
  unused for-loop index i.
  internal/modules/cjs/loader.js:983
  throw err;
  ^

Error: Cannot find module 'bs-platform/lib/js/string.js'
Require stack:
- /tmp/code.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:980:15)
    at Function.Module._load (internal/modules/cjs/loader.js:862:27)
    at Module.require (internal/modules/cjs/loader.js:1042:19)
    at require (internal/modules/cjs/helpers.js:77:18)
    at Object.<anonymous> (/tmp/code.js:4:16)
    at Module._compile (internal/modules/cjs/loader.js:1156:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1176:10)
    at Module.load (internal/modules/cjs/loader.js:1000:32)
    at Function.Module._load (internal/modules/cjs/loader.js:899:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:74:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ '/tmp/code.js' ]
}

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7fff315ffd60 /* 9 vars */) = 0
11    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x55eada392d18 /* 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/ln", ["ln", "-sf", "/volume/CODE", "/tmp/code.re"], 0x55eada392d38 /* 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} ---
13    execve("/usr/bin/bsc", ["/usr/bin/bsc", "/tmp/code.re"], 0x55eada392d20 /* 9 vars */) = 0
13    execve("/bin/node", ["node", "/usr/bin/bsc", "/tmp/code.re"], 0x7ffe1add0b70 /* 9 vars */) = -1 ENOENT (No such file or directory)
13    execve("/usr/local/sbin/node", ["node", "/usr/bin/bsc", "/tmp/code.re"], 0x7ffe1add0b70 /* 9 vars */) = -1 ENOENT (No such file or directory)
13    execve("/usr/local/bin/node", ["node", "/usr/bin/bsc", "/tmp/code.re"], 0x7ffe1add0b70 /* 9 vars */) = -1 ENOENT (No such file or directory)
13    execve("/usr/sbin/node", ["node", "/usr/bin/bsc", "/tmp/code.re"], 0x7ffe1add0b70 /* 9 vars */) = -1 ENOENT (No such file or directory)
13    execve("/usr/bin/node", ["node", "/usr/bin/bsc", "/tmp/code.re"], 0x7ffe1add0b70 /* 9 vars */) = 0
20    execve("/usr/lib/node_modules/bs-platform/linux/bsc.exe", ["/usr/lib/node_modules/bs-platfor"..., "/tmp/code.re"], 0x55678e024f60 /* 9 vars */) = 0
21    execve("/bin/sh", ["sh", "-c", "/usr/lib/node_modules/bs-platfor"...], 0x7ffca1610800 /* 9 vars */) = 0
21    execve("/usr/lib/node_modules/bs-platform/linux/refmt.exe", ["/usr/lib/node_modules/bs-platfor"..., "--print=binary", "/tmp/code.re"], 0x5611fd215090 /* 9 vars */) = 0
21    +++ exited with 0 +++
20    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=21, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
20    +++ exited with 0 +++
13    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=20, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
15    +++ exited with 0 +++
16    +++ exited with 0 +++
18    +++ exited with 0 +++
17    +++ exited with 0 +++
14    +++ exited with 0 +++
19    +++ exited with 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=3, si_stime=1} ---
22    execve("/bin/cat", ["cat", "-"], 0x55eada392d38 /* 9 vars */ <unfinished ...>
23    execve("/usr/bin/node", ["/usr/bin/node", "/tmp/code.js"], 0x55eada392d48 /* 9 vars */ <unfinished ...>
22    <... execve resumed>)             = 0
23    <... execve resumed>)             = 0
22    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=22, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
25    +++ exited with 0 +++
26    +++ exited with 0 +++
24    +++ exited with 0 +++
27    +++ exited with 0 +++
28    +++ exited with 0 +++
29    +++ exited with 1 +++
23    +++ exited with 1 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=23, si_uid=0, si_status=1, si_utime=4, si_stime=0} ---
30    execve("/bin/rm", ["rm", "/tmp/code.js", "/tmp/code.re"], 0x55eada392cf0 /* 9 vars */) = 0
30    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=30, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
10    +++ exited with 0 +++