python3, 68 bytes

Result

AC

Duration

790ms

Code [DL]

while s:=input():
    if s[1]!=s[2]:print(s[4])
    else:print(s[2])

stdin

844 342
151 452
168 932
592 487
614 115
799 996
372 221
649 947
631 211
134 889
877 125
211 614
157 588
356 613
475 597
819 192
349 751
762 635
577 763
956 151
877 126
182 258
269 967
791 449
667 775
744 119
272 771
622 235
477 229
474 948
136 364
877 776

stdout

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

stderr

Traceback (most recent call last):
  File "/volume/CODE", line 1, in <module>
    while s:=input():
EOFError: EOF when reading a line

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffcf6ea99f0 /* 7 vars */) = 0
12    execve("/bin/cat", ["cat", "-"], 0x55fefb8c6d38 /* 7 vars */ <unfinished ...>
13    execve("/usr/bin/python3", ["/usr/bin/python3", "/volume/CODE"], 0x55fefb8c6d50 /* 7 vars */ <unfinished ...>
12    <... execve resumed>)             = 0
13    <... execve resumed>)             = 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    +++ exited with 1 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
11    +++ exited with 1 +++