Description

Charlie is taking a course called Basics of Abstract Strings.

Definition 3.1: For two lowercase strings $S$ and $T$ of the same length, their similarity is defined as the number of matching characters in corresponding positions. Formally, if $|S| = |T| = n$, then the similarity between $S$ and $T$ is given by $\psi(S, T) = \sum\limits_{i=1}^n \sum\limits_{j=1}^n [i = j][S_i = T_j]$.

Lemma 3.1: For any lowercase string $S$, there exists a unique lowercase string $T$ that maximizes $\psi(S, T)$.

Proof of Lemma 3.1: ...

Charlie’s mind begins to wander, and he starts scribbling aimlessly on his paper. Suddenly, he comes up with a new idea: what if he defines the dissimilarity between $S$ and $T$ as the number of pairs where both the position and the character are different? Formally, this similarity can be defined as $\tilde{\psi}(S, T) = \sum\limits_{i=1}^n \sum\limits_{j=1}^n [i \neq j][S_i \neq T_j]$. This whimsical definition snaps Charlie out of his daydream. Now, he wonders: what kind of lowercase string $T$ would maximize the dissimilarity between $S$ and $T$?

Note: The square brackets $[x]$ represent Iverson brackets, which evaluate to $1$ if the condition $x$ is true, and $0$ otherwise.

Input Format

The first line contains a positive integer $n$.

The second line contains a string $S$ of length $n$, consisting only of lowercase letters.

Output Format

Output a single line containing a lowercase string $T$, representing your answer. You need to maximize the dissimilarity between $S$ and $T$. If there are multiple answers, output any.

9
cbbccxxxx

godfather

26
abcdefghijklmnopqrstuvwxyz

abcdefghijklmnopqrstuvwxyz

28
aabcdefghijklmnopqrstuvwxyzz

cybcdefghijklmnopqrstuvwxycy

Hint

Sample $1$ Explanation

When $T = \texttt{godfather}$, $\tilde{\psi}(S, T) = 72$, reaching the maximum value. Note that there may be more than one valid answer.

Subtasks and Constraints

For all tests, it is guaranteed that:

• $1 \le n \le 10^6$;
• $S$ consists only of lowercase letters.