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

S[K-1] = chr(ord(S[K-1]) + 32)

print("".join(S)) 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] = chr(ord(S[K-1]) + 32) S[K-1] S K-1 K 1 chr(ord(S[K-1]) + 32) chr ord(S[K-1]) + 32 ord(S[K-1]) ord S[K-1] S K-1 K 1 32 print("".join(S)) print "".join(S) "".join "" join S S = list(input()) list(input()) S K = map(int, input().split()) map(int, input().split()) K N, K = map(int, input().split()) map(int, input().split()) N
N, K = map(int, input().split())
S = list(input())

S[K-1] = chr(ord(S[K-1]) + 32)

print("".join(S))