perl, 28 bytes

Result

AC

Duration

854ms

Code [DL]

print/(.)\1 /?$1:/ ./g for<>

stdin

844 848
115 596
787 873
177 771
282 285
349 232
149 946
398 912
879 376
316 832
611 157
347 445
178 889
411 172
833 211
118 442
988 688
145 452
653 239
799 771
542 929
486 699
218 398
756 536
752 652
955 446
384 773
846 664
243 448
822 226
255 129
581 637

stdout

4 5 87 2 2 9 9 3 81 4 813 48 4 29 9 6 3 5 65 7 6 425 6

stderr

strace

10    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffca57efb10 /* 7 vars */) = 0
11    execve("/bin/cat", ["cat", "-"], 0x55f69335dd30 /* 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    execve("/usr/bin/perl", ["/usr/bin/perl", "/volume/CODE"], 0x55f69335dd40 /* 7 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} ---
10    +++ exited with 0 +++