s/ / < /
h
:1
s/.<./</
t1
/.</{g;s/</>/;b}
/<./{g;b}
g
:2
s/^\(.\)\(.*< \)\1/\2/
t2
/^ /{g;s/</=/;b}
s/^/0123456789 /
/\(.\)\(.\)*.* \1.* \2/{g;b}
g;s/</>/