N, K = map(int, input().split())
S = list(input())
S[K-1] = S[K-1].lower()
for i in S:
    print(i, end="") N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K S = list(input()) S list(input()) list input() input S[K-1] = S[K-1].lower() S[K-1] S K-1 K 1 S[K-1].lower() [K-1].lower [K-1] S K-1 K 1 lower for i in S:
    print(i, end="") i S print(i, end="") print i end="" end "" N, K = map(int, input().split()) map(int, input().split()) N K = map(int, input().split()) map(int, input().split()) K S = list(input()) list(input()) S
N, K = map(int, input().split())
S = list(input())
S[K-1] = S[K-1].lower()
for i in S:
    print(i, end="")