Problem
Prosciutto loves to wear pendants. He especially likes the ones with inscriptions of words consisting of lowercase Latin letters, so he only wears these.
Prosciutto wanted to buy himself a new pendant and went to a special store.
In the store, he was told that pendants with palindrome inscriptions are especially in fashion now. Of course, Prosciutto decided to choose one for himself, but he could not decide on a choice.
Then he was told an ancient custom, which says that you need to take a word from the inscription on the current pendant, come up with a pleasant word of the same length and transform them into a word for the inscription on the new pendant.
The transformation operation is as follows:
1) Symbols in the corresponding positions are assigned numbers that correspond to the positions of these symbols in the alphabet. So the letter d will correspond to the number 4, and the letter a - 1.
2) The numbers in the corresponding positions are added up. If the amount exceeds the size of the Latin alphabet, then 26 is subtracted from it.
3) A letter is added to the new word, which corresponds to the received amount.
Thus the words "aba" and "bab" are transformed into "ccc", and "zxc" and "bbb" in "bze".
Prosciutto now has a pendant with the inscription s of length n, but pleasant words do not come to his mind. However, he thought it would be interesting to take the lexicographically minimal word to transform the current caption into a trendy palindromic caption.
Despite the fact that Prosciutto's current pendant might already have a palindrome inscription, Prosciutto still wants to choose a new one.
Prosciutto did not sleep much today, so he cannot determine with which word he needs to transform the current inscription. Please help him.
Input:
The first line contains a natural number n (1 ≤ n ≤ 10
5) - the length of the inscription on the current Prosciutto pendant.
The second line contains the string s - the inscription itself.
Output:
Print a single line - a word of the same length with which you need to transform the existing caption to get a palindromic caption.
Examples:
| Input |
Output |
2
ad |
ax |
7
abacaba |
aaaaaaa |
Explanation:
In the first example, the word "ax" - lexicographically minimal, with which you can transform the existing inscription "ad" to get a palindromic inscription (it will be "bb").