N, K = map(int, input().split())
s3 =[]

s = list(input())

s1 = s


s2= s1[K-1]

s3 = s2.lower()

s1[K-1] = s3

print('' .join(s1)) N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K s3 =[] s3 [] s = list(input()) s list(input()) list input() input s1 = s s1 s s2= s1[K-1] s2 s1[K-1] s1 K-1 K 1 s3 = s2.lower() s3 s2.lower() s2.lower s2 lower s1[K-1] = s3 s1[K-1] s1 K-1 K 1 s3 print('' .join(s1)) print '' .join(s1) '' .join '' join s1 s1 = s s s1 s3 = s2.lower() s2.lower() s3 s3 =[] [] s3 s = list(input()) list(input()) s N, K = map(int, input().split()) map(int, input().split()) N K = map(int, input().split()) map(int, input().split()) K s2= s1[K-1] s1[K-1] s2
N, K = map(int, input().split())
s3 =[]

s = list(input())

s1 = s


s2= s1[K-1]

s3 = s2.lower()

s1[K-1] = s3

print('' .join(s1))