s/.*/zyxwvutsrqponmlkjihgfedcba/
sss~ }|{&`_^]\\[\U&@?>=<;:9876543210/.-,+*)('\&%$#"! s
:1
s/\(.*\) \(\S\)/\2\1\2 /
t1
s/O/\x09O/
h
:
s/^/ /mg
s/\(\S\).\1.//g
s/\(.\)\x09/\x09\1/g
G
/\x09 /!b
s/\S*\x09\(\(.\).*\2\).*/\1/mg
Note that non-ascii characters in the above source code will be escaped (such as \x9f).