lua, 54 bytes

Result

AC

Duration

794ms

Code [DL]

::_::print(io.read():match"((.?)%2 .)":sub(2,2))goto _

stdin

329 224
247 267
653 334
522 229
633 785
524 147
838 991
593 337
298 897
455 253
943 643
362 825
485 932
611 117
919 112
852 593
664 165
514 148
583 343
411 779
188 227
794 858
121 129
547 683
422 233
662 238
361 618
688 842
155 652
564 118
488 947
256 544

stdout

2
2
3
2
3
1
9
3
8
5
6
8
9
1
1
5
1
1
3
1
8
8
1
6
2
2
6
8
5
1
8
5

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"], 0x7ffeb4ee8b90 /* 7 vars */) = 0
12    execve("/usr/bin/lua5.3", ["/usr/bin/lua5.3", "/volume/CODE"], 0x563a9afcbd40 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x563a9afcbd30 /* 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 +++