lua, 47 bytes

Result

WA

Duration

1128ms

Code [DL]

print(io.read'*a':gsub("%S+(%d)[%1 ]%S+","%1"))

stdin

911 852
195 561
788 361
861 175
117 779
112 572
831 236
998 885
466 697
483 579
822 228
955 527
971 174
411 112
469 113
611 914
982 884
227 873
151 519
553 957
477 629
945 151
461 166
845 418
966 969
533 225
733 775
572 722
837 662
718 166
477 661
128 228

stdout

1
5
8
1
7
2
1
8
6
3
2
5
1
1
9
1
2
7
1
3
7
5
1
5
6
3
3
2
7
8
7
8
	32

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffe9c087090 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x5561b6645d30 /* 7 vars */ <unfinished ...>
12    execve("/usr/bin/lua5.3", ["/usr/bin/lua5.3", "/volume/CODE"], 0x5561b6645d40 /* 7 vars */ <unfinished ...>
11    <... execve resumed>)             = 0
12    <... execve resumed>)             = 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    +++ 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} ---
10    +++ exited with 0 +++