Problem:
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.

Sample Input 1

3 1
ABC

Sample Output 1

aBC

Sample Input 2

4 3
CABA

Sample Output 2

CAbA

Solution in JavaScript (node.js v5.12) (judge verdict: Runtime Error)

function main(input) {
  let args = input.split('\n');
  let k = args[0].split(' ')[1];
  let s = args[1].split('');
  
  s[k - 1] = s[k - 1].toLowerCase();
  s = s.join('');
  console.log(s);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));