Problem B: Rolling Encryption

You have a sequence of lowercase characters that you want to encrypt.

The first k characters will be encoded as plain-text. All characters after the first k characters will be shifted by the most frequently occuring character that appeared in the previous k characters, with ties broken by the character which occurs first in the alphabet. By "shifted by", we mean that if c was the most frequently occuring character, the character would be shifted ahead by 3 positions (since c is the third letter of the alphabet), modulo 26 (e.g., b becomes e, and z becomes c).

Input Specification

On the first line of input contains k (1 ≤ k ≤ 10 000). The next line contains c characters (1 ≤ c ≤ 100 000).

Output Specification

One line, containing the encrypted version of the c characters from the input.

Sample Input

5
abbaabbacdecde

Output for Sample Input

abbaacdcdegdgh

Troy Vasiga

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