lua, 46 bytes

Result

WA

Duration

766ms

Code [DL]

::a::print(io.read():match"(.) ?%1"or 1)goto a

stdin

699 996
584 188
449 983
636 364
393 871
655 556
775 553
368 287
513 713
161 663
961 168
761 172
188 778
829 552
166 955
958 974
594 947
922 689
386 871
485 755
188 987
543 348
887 772
599 883
844 499
161 637
588 189
881 884
833 346
656 842
543 991
429 314

stdout

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

stderr

/usr/bin/lua5.3: /volume/CODE:1: attempt to index a nil value
stack traceback:
	/volume/CODE:1: in main chunk
	[C]: in ?

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7fffa84f2820 /* 7 vars */) = 0
12    execve("/usr/bin/lua5.3", ["/usr/bin/lua5.3", "/volume/CODE"], 0x55d1a2d8fd40 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x55d1a2d8fd30 /* 7 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    +++ exited with 1 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=1, si_utime=0, si_stime=0} ---
10    +++ exited with 1 +++