node, 91 bytes

Result

WA

Duration

820ms

Code [DL]

console.log((""+require("fs").readFileSync(0)).split`
`.map(s=>s[2]-s[3]?s[4]:s[2]).join``)

stdin

515 413
176 626
544 731
921 997
773 774
255 355
528 564
345 526
354 571
785 374
466 577
822 552
293 395
991 195
688 824
116 463
792 928
177 778
211 116
639 331
265 652
945 835
166 165
655 519
568 887
738 881
778 939
656 269
799 669
536 376
424 127
826 992

stdout

46797355535531849713681588926319

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffc8790d960 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x5611c7eb8d30 /* 7 vars */) = 0
12    execve("/usr/bin/node", ["/usr/bin/node", "/volume/CODE"], 0x5611c7eb8d40 /* 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} ---
14    +++ exited with 0 +++
15    +++ exited with 0 +++
17    +++ exited with 0 +++
16    +++ 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=4, si_stime=1} ---
10    +++ exited with 0 +++