node, 126 bytes

Result

AC

Duration

675ms

Code [DL]

for(s of(""+require("fs").readFileSync(0)).split(/\n/))if(s)console.log((s+"a").slice(0,s.indexOf("__")).match(/\|/g).length);

stdin

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

stdout

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

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffc6452efb0 /* 7 vars */) = 0
12    execve("/usr/bin/node", ["/usr/bin/node", "/volume/CODE"], 0x55e34a80cd40 /* 7 vars */ <unfinished ...>
11    execve("/bin/cat", ["cat", "-"], 0x55e34a80cd30 /* 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    <... execve resumed>)             = 0
17    +++ exited with 0 +++
16    +++ exited with 0 +++
14    +++ exited with 0 +++
15    +++ exited with 0 +++
18    +++ exited with 0 +++
13    +++ 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=7, si_stime=1} ---
10    +++ exited with 0 +++