golang, 106 bytes

Result

AC

Duration

1526ms

Code [DL]

package main
import."fmt"
func main(){a,b:=0,0;Scan(&a,&b);if a>0{if b%110<9{a=b/100};Print(a%10);main()}}

stdin

321 712
369 953
566 698
651 545
177 669
317 174
876 173
161 683
265 775
832 228
384 458
947 911
688 843
977 934
513 115
281 815
185 255
148 889
396 793
545 998
359 951
611 213
961 163
411 695
366 443
188 589
266 935
155 556
822 226
963 594
837 219
631 336

stdout

19617761724787115869911148652373

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffd9a7d76e0 /* 7 vars */) = 0
12    execve("/usr/bin/realpath", ["realpath", "/volume/CODE"], 0x561a89649d18 /* 7 vars */) = 0
12    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
13    execve("/bin/ln", ["ln", "-sf", "/volume/CODE", "/tmp/code.go"], 0x561a89649d38 /* 7 vars */) = 0
13    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
14    execve("/usr/bin/go", ["/usr/bin/go", "build", "-o", "/tmp/code", "/tmp/code.go"], 0x561a8aa61028 /* 7 vars */) = 0
21    execve("/usr/lib/go/pkg/tool/linux_amd64/compile", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-V=full"], 0xc000351040 /* 25 vars */) = 0
22    execve("/usr/lib/go/pkg/tool/linux_amd64/compile", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-V=full"], 0xc0001284e0 /* 25 vars */) = 0
24    +++ exited with 0 +++
26    +++ exited with 0 +++
25    +++ exited with 0 +++
23    +++ exited with 0 +++
21    +++ exited with 0 +++
20    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=21, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
28    +++ exited with 0 +++
30    +++ exited with 0 +++
27    +++ exited with 0 +++
22    +++ exited with 0 +++
17    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=22, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
29    execve("/usr/lib/go/pkg/tool/linux_amd64/asm", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-V=full"], 0xc0003511e0 /* 25 vars */) = 0
31    execve("/usr/lib/go/pkg/tool/linux_amd64/asm", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-V=full"], 0xc000128750 /* 25 vars */) = 0
32    ????( <unfinished ...>
34    +++ exited with 0 +++
33    +++ exited with 0 +++
35    +++ exited with 0 +++
32    +++ exited with 0 +++
29    +++ exited with 0 +++
20    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=29, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
39    +++ exited with 0 +++
38    +++ exited with 0 +++
37    +++ exited with 0 +++
36    +++ exited with 0 +++
31    +++ exited with 0 +++
17    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=31, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
40    execve("/usr/lib/go/pkg/tool/linux_amd64/compile", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-o", "/tmp/go-build718534517/b001/_pkg"..., "-trimpath", "/tmp/go-build718534517/b001=>", "-p", "main", "-complete", "-buildid", "r44NQMVn5J1jpQ2WEwlr/r44NQMVn5J1"..., "-goversion", "go1.13.10", "-D", "_/tmp", "-importcfg", "/tmp/go-build718534517/b001/impo"..., "-pack", "-c=2", "/tmp/code.go"], 0xc0002601a0 /* 25 vars */) = 0
42    +++ exited with 0 +++
43    +++ exited with 0 +++
41    +++ exited with 0 +++
40    +++ exited with 0 +++
20    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=40, si_uid=0, si_status=0, si_utime=1, si_stime=0} ---
44    execve("/usr/lib/go/pkg/tool/linux_amd64/link", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-V=full"], 0xc0004485b0 /* 25 vars */) = 0
47    +++ exited with 0 +++
45    +++ exited with 0 +++
46    +++ exited with 0 +++
44    +++ exited with 0 +++
17    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=44, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
48    execve("/usr/lib/go/pkg/tool/linux_amd64/link", ["/usr/lib/go/pkg/tool/linux_amd64"..., "-o", "/tmp/go-build718534517/b001/exe/"..., "-importcfg", "/tmp/go-build718534517/b001/impo"..., "-buildmode=exe", "-buildid=aCEFiCOManLuqB50x_bx/r4"..., "-extld=gcc", "/tmp/go-build718534517/b001/_pkg"...], 0xc0004489c0 /* 25 vars */) = 0
52    +++ exited with 0 +++
51    +++ exited with 0 +++
50    +++ exited with 0 +++
49    +++ exited with 0 +++
48    +++ exited with 0 +++
20    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=48, si_uid=0, si_status=0, si_utime=20, si_stime=3} ---
19    +++ exited with 0 +++
15    +++ exited with 0 +++
53    +++ exited with 0 +++
20    +++ exited with 0 +++
17    +++ exited with 0 +++
16    +++ exited with 0 +++
18    +++ exited with 0 +++
14    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=0, si_utime=8, si_stime=14} ---
54    execve("/bin/cat", ["cat", "-"], 0x561a89649d08 /* 7 vars */) = 0
55    execve("/tmp/code", ["/tmp/code"], 0x561a89649cf0 /* 7 vars */) = 0
54    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=54, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
56    +++ exited with 0 +++
59    +++ exited with 0 +++
58    +++ exited with 0 +++
57    +++ exited with 0 +++
55    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=55, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
60    execve("/bin/rm", ["rm", "/tmp/code.go", "/tmp/code"], 0x561a89649cf0 /* 7 vars */) = 0
60    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=60, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
11    +++ exited with 0 +++