num = input().split()

N = int(num[0])
K = int(num[1])

S = input()

S2 = S[K-1]

S = S[:K-1] + S2.lower() + S[K:]

print(S) num = input().split() num input().split() ().split () input split N = int(num[0]) N int(num[0]) int num[0] num 0 K = int(num[1]) K int(num[1]) int num[1] num 1 S = input() S input() input S2 = S[K-1] S2 S[K-1] S K-1 K 1 S = S[:K-1] + S2.lower() + S[K:] S S[:K-1] + S2.lower() + S[K:] S[:K-1] + S2.lower() S[:K-1] S :K-1 K-1 K 1 S2.lower() S2.lower S2 lower S[K:] S K: K print(S) print S K = int(num[1]) int(num[1]) K num = input().split() input().split() num S2 = S[K-1] S[K-1] S2 N = int(num[0]) int(num[0]) N S = input() input() S S = S[:K-1] + S2.lower() + S[K:] S[:K-1] + S2.lower() + S[K:] S
num = input().split()

N = int(num[0])
K = int(num[1])

S = input()

S2 = S[K-1]

S = S[:K-1] + S2.lower() + S[K:]

print(S)