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