python3, 40 bytes

Result

WA

Duration

932ms

Code [DL]

for s in open(0):print(s[s.index(s[2])])

stdin

432 224
386 886
132 382
766 668
188 229
788 293
917 113
472 161
855 851
446 461
119 811
886 489
866 623
455 554
282 126
577 711
748 842
314 778
168 437
731 314
217 289
677 967
522 771
782 923
498 845
154 466
718 811
124 667
787 795
112 154
844 742
818 882

stdout

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

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7fff79bca6e0 /* 7 vars */) = 0
12    execve("/bin/cat", ["cat", "-"], 0x5614029dbd38 /* 7 vars */) = 0
13    execve("/usr/bin/python3", ["/usr/bin/python3", "/volume/CODE"], 0x5614029dbd50 /* 7 vars */ <unfinished ...>
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 resumed>)             = 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=1, si_stime=1} ---
11    +++ exited with 0 +++