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 Python (3.4.3) (judge verdict: Accepted)


N,K=map(int,input().split())

S=str(input())
q=S[K-1]
#print(q)

if q == "A":
    w="a"
elif q=="B":
    w="b"
else:
    w="c"
e=""
for i in range(N):
    if i != K-1:
        e=e+S[i]
    else:
        e=e+w
print(e)