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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

uses crt;
var n,k:longint;
    s:string;
begin
        clrscr;
        readln(n,k);
        readln(s);
        s[k]:=chr(ord(s[k])+32);
        write(s);
        readln

end.