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'
function Main(input) {
    input = input.split("\n")
    const lineOne = input[0].split(' ').map(str => parseInt(str, 10))
    const S = input[1]
    const K = lineOne[1] - 1
 
    let strings = S.split('')
    strings[K] = strings[K].toLowerCase()
    const result = strings.join('')
    
    console.log(result)
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"))