php, 49 bytes

Result

WA

Duration

861ms

Code [DL]

<?=x;for(;$a=readline();)echo$a[$a[1]-$a[2]?4:1];

stdin

386 257
743 737
456 618
517 361
262 885
678 846
453 669
181 896
788 811
593 998
566 976
941 144
199 711
766 365
392 795
462 827
299 996
744 411
923 768
433 445
534 448
466 882
219 993
686 586
655 174
487 878
811 618
229 227
496 955
737 734
569 698
177 774

stdout

x27638868896196789473469558129767

stderr

PHP Warning:  Use of undefined constant x - assumed 'x' (this will throw an Error in a future version of PHP) in /volume/CODE on line 1

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffd7190ede0 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x55f3b0ed9d30 /* 7 vars */) = 0
12    execve("/usr/bin/php", ["/usr/bin/php", "/volume/CODE"], 0x55f3b0ed9d40 /* 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    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=1} ---
10    +++ exited with 0 +++