node, 138 bytes

Result

AC

Duration

707ms

Code [DL]

for(s of (""+require("fs").readFileSync(0)).slice(0,-1).split(/\n/)){
console.log((s+"a").slice(0,s.indexOf("__")).split("|").length-1);
}

stdin

|__|||_|__
|_|_|__|_|
||__|__|__
|__|______
|__|_|____
|___||__|_
|||_____||
|||||||__|
|_||___||_
|__|_||||_
|_|_|_||__
|_||||_|__
|||||||_||
|_|_|||__|
|__|_|___|
|__|____|_
||||__|___
|||_|__|||
|||__|__||
||__|||_||
||||||||||
||_|||||_|
||___||||_
|_||_|||_|
|||_||_||_
|__|||____
|||___|_|_
|___|___||
|_____|__|
|___||__||

stdout

1
3
2
1
1
1
3
7
3
1
5
6
9
5
1
1
4
4
3
2
10
8
2
7
7
1
3
1
1
1

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffc7139ead0 /* 7 vars */) = 0
12    execve("/usr/bin/node", ["/usr/bin/node", "/volume/CODE"], 0x55b957f13d40 /* 7 vars */ <unfinished ...>
11    execve("/bin/cat", ["cat", "-"], 0x55b957f13d30 /* 7 vars */) = 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} ---
17    +++ exited with 0 +++
16    +++ exited with 0 +++
14    +++ exited with 0 +++
15    +++ exited with 0 +++
13    +++ exited with 0 +++
18    +++ exited with 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=5, si_stime=2} ---
10    +++ exited with 0 +++