A - Changing a Character

Score : $100$ points

Problem Statement

You are given a string $S$ of length $N$ consisting of A, B and C, and an integer $K$ which is between $1$ and $N$ (inclusive). Print the string $S$ after lowercasing the $K$-th character in it.

Constraints

• $1 ≤ N ≤ 50$
• $1 ≤ K ≤ N$
• $S$ is a string of length $N$ consisting of A, B and C.

Input

Input is given from Standard Input in the following format:

$N$ $K$

$S$

Output

Print the string $S$ after lowercasing the $K$-th character in it.

3 1
ABC

aBC

4 3
CABA

CAbA