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: Runtime Error)

var N,K:integer;
    S:string;
begin
read(N,K,S);
if S[K]='A' then S[K]:='a';
if S[K]='B' then S[K]:='b';
if S[K]='C' then S[K]:='c';
write(S)
end.