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: Accepted)

'use strict'

const main = (INPUT) => {
  const input = INPUT.split('\n')
  const K = Number(input[0].split(' ')[1])

  let S = input[1].split('')

  S[K - 1] = S[K - 1].toLowerCase()
  console.log(S.join(''))
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))