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 C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
int main()
{
   int N,K,cnt,sabun,ptA,ptB,tmp;
   char s[60];
    //char s[101];
    // 整数の入力
    scanf("%d %d", &N,&K);
    scanf("%s",&s);
    s[K-1]= s[K-1]+0x20;

    // 文字列の入力
    printf("%s\n",s);

    // 出力
    //printf("%d %s\n",a+b+c,s);
   return 0;
}