http://www.perlmonks.org?node_id=406428


in reply to Golf: ROT-n

Fore! 38 strokes...
#23456789_123456789_123456789_12345678 $_=pop;for$x(1..pop){y/a-z/b-za/}print

UPDATE: Looking at other solutions inspired an improvement to 36 strokes.
#23456789_123456789_123456789_123456 $_=pop;eval"y/a-z/b-za/;"x pop;print