vim, 34 bytes

Result

AC

Duration

810ms

Code [DL]

:%s/\v.((.)\2 .|.. (.))../\2\3
ZZ

Disassembly

:%s/\v.((.)\2 .|.. (.))../\2\3<NL>ZZ<NL>

stdin

566 331
963 931
791 115
419 738
755 153
926 297
214 415
423 224
544 482
624 493
166 465
143 537
288 887
796 334
359 157
192 922
571 146
524 424
755 631
332 223
358 449
859 311
515 411
969 697
299 982
878 146
539 659
722 227
511 441
279 776
558 517
811 387

stdout

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

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7fff381a2a80 /* 9 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x55ac1ff93d00 /* 9 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("/usr/bin/vim", ["/usr/bin/vim", "-N", "-u", "NONE", "-i", "NONE", "-s", "/volume/CODE", "/tmp/out"], 0x55ac20f72288 /* 10 vars */) = 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=0} ---
13    execve("/bin/cat", ["cat", "/tmp/out"], 0x55ac1ff93c98 /* 9 vars */) = 0
13    +++ exited with 0 +++
10    --- 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("/bin/rm", ["rm", "/tmp/out"], 0x55ac1ff93c98 /* 9 vars */) = 0
14    +++ exited with 0 +++
10    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
10    +++ exited with 0 +++