node, 75 bytes

Result

WA

Duration

878ms

Code [DL]

console.log((""+require("fs").readFileSync(0)).replace(/.+(.)\1?.+/g,"$1"))

stdin

176 778
788 967
879 884
731 342
551 191
489 599
438 113
744 274
719 153
622 927
622 324
766 668
391 798
937 921
863 638
413 327
832 348
316 114
188 835
696 667
722 771
433 381
176 747
658 585
276 679
385 554
965 456
233 336
593 416
988 119
375 571
687 385

stdout

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

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7fff10b282b0 /* 7 vars */) = 0
12    execve("/bin/cat", ["cat", "-"], 0x5652129a5d30 /* 7 vars */ <unfinished ...>
13    execve("/usr/bin/node", ["/usr/bin/node", "/volume/CODE"], 0x5652129a5d40 /* 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} ---
15    +++ exited with 0 +++
16    +++ exited with 0 +++
18    +++ exited with 0 +++
17    +++ exited with 0 +++
14    +++ exited with 0 +++
19    +++ exited with 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=5, si_stime=1} ---
11    +++ exited with 0 +++