Oscar has two strings of length ~N~, string ~a~ and string ~b~. He wonders the following question:

Is it possible to turn string ~a~ into string ~b~ by substituting all instances of one letter with another letter?

Input Specification

The first line of input contains an integer, ~N (1 \le N \le 2 \times 10^{6})~. The second line of input contains a string, ~a~. The third line of input contains a string, ~b~.

Strings ~a~ and ~b~ will consist of lowercase letters only.

Output Specification

Output yes or no in response to Oscar's question.

Sample Input 1

5
enels
nnnls

Sample Output 1

yes

Explanation

If you replace all occurences of e in string ~a~ with n, you get string ~b~.

Sample Input 2

5
enels
enenn

Sample Output 2

no

Explanation

There is no way to make string ~a~ the same as string ~b~ by replacing all instances of one letter with another. If you were to replace all instances of l with n, you would get the string enens. If you were to replace all instances of s with n, you would get the string eneln. Neither of these results equal the target string, enenn.

Sample Input 3

5
enels
ennls

Sample Output 3

no

Explanation

There is no way to make string ~a~ the same as string ~b~ by replacing all instances of one letter with another. If you were to replace all instances of e with n, you get the string nnnls, which doesn't equal the target string, ennls.