perl6, 49 bytes

Result

AC

Duration

1228ms

Code [DL]

$_~|($||=$_)~~{say S[k\s+]='k'x$/.codes}for lines

stdin

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          K                                       

stdout

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          kkkkkkkkkkkkkkkkkkkkkkkt                

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffeb2ef9240 /* 7 vars */) = 0
13    execve("/usr/bin/perl6", ["/usr/bin/perl6", "/volume/CODE"], 0x55ce1c091d40 /* 7 vars */) = 0
13    execve("/usr/bin/moar", ["/usr/bin/moar", "--execname=/usr/bin/perl6", "--libpath=/usr/share/nqp/lib", "--libpath=/usr/share/nqp/lib", "--libpath=/usr/share/perl6/lib", "--libpath=/usr/share/perl6/runti"..., "/usr/share/perl6/runtime/perl6.m"..., "/volume/CODE"], 0x5615ffee20c0 /* 7 vars */) = 0
12    execve("/bin/cat", ["cat", "-"], 0x55ce1c091d30 /* 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} ---
14    +++ exited with 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=32, si_stime=11} ---
11    +++ exited with 0 +++