oh, 91 bytes

Result

AC

Duration

934ms

Code [DL]

define a:""::split:readline
echo:if(eq(a::get 1):a::get 2)(a::get 1)else:a::get 4
source $0

stdin

328 244
677 779
432 554
834 443
957 399
931 332
699 441
179 575
711 138
977 772
961 611
665 663
644 941
551 184
747 779
516 619
177 524
788 893
656 363
554 456
837 985
139 659
747 471
166 225
982 848
988 726
612 881
536 167
598 553
953 258
822 726
732 261

stdout

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

stderr

boot.oh: 360: error/runtime: argument 1 (of 1) is invalid

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffe24682800 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x55638f9ab048 /* 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} ---
13    execve("/usr/bin/go", ["/usr/bin/go", "env", "GOPATH"], 0x55638f9ab078 /* 7 vars */) = 0
14    +++ exited with 0 +++
15    +++ exited with 0 +++
16    +++ exited with 0 +++
17    +++ exited with 0 +++
13    +++ exited with 0 +++
12    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
12    execve("/root/go/bin/oh", ["/root/go/bin/oh", "/volume/CODE"], 0x55638f9ab068 /* 7 vars */) = 0
23    +++ exited with 0 +++
22    +++ exited with 0 +++
21    +++ exited with 0 +++
20    +++ exited with 0 +++
19    +++ 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=3, si_stime=5} ---
10    +++ exited with 0 +++