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

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

print(S[:K-1] + tmp + S[K:])
