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: Wrong Answer)

inputS = input()
s = inputS

if int(s[-2:]) == 0 or int(s[:2]) == 0:
    print("NA")
elif int(s[-2:]) <= 12 and int(s[:2]) <= 12:
    print("AMBIGUOUS")
elif int(s[:2]) > 12 and int(s[-2:]) <= 12:
    print("YYMM")
elif int(s[:2]) <= 12 and int(s[-2:]) > 12:
    print("MMYY")
elif int(s[:2]) > 12 and int(s[-2:]) >12:
    print("NA")