s/^\(.*\) \1/\1 = \1/
te
h
s/..\(.*\)../\1/
:a
/^ $/bs
/^ /bl
/ $/bg
s/.\(.* \)./\1/
ba
:s
x
h
:q
s/^\(.\)\(.* \)\1/\2/
tq
s/$/@9876543210/
/^\(.\).* \(.\).*@.*\1.*\2/bg
:l
x
s/ / < /
be
:g
x
s/ / > /
:e