#!/usr/bin/env -S sbcl --script

(format t "~d~%"
    (length (delete-duplicates
         (loop repeat (read) collect (read-line))
         :test (lambda (a b)
             (and (string= (sort a #'char<) (sort b #'char<))
                (char= (char a 0) (char b 0))
                (char= (char a (1- (length a))) (char b (1- (length b)))))))))
>>445
Common Lisp HyperSpecではSide Effects: None.となっているけれど。