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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.util.*;

class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    ArrayList<String> x = new ArrayList<>();
    int n = sc.nextInt();
    int k = sc.nextInt();
    
    for(int i = 0;i < n;i++){
		x.add(sc.nextLine());
    }
    String lower = x.get(k - 1).toLowerCase();
    x.set(k - 1,lower);
    
    for(String i : x){
      System.out.print(i);
    }
  }
}