N,K = map(int,input().split())
s = input()
new = s[:K-1] + s[K-1].lower() + s[K:]
print(new) N,K = map(int,input().split()) N map(int,input().split()) map int input().split() ().split () input split K s = input() s input() input new = s[:K-1] + s[K-1].lower() + s[K:] new s[:K-1] + s[K-1].lower() + s[K:] s[:K-1] + s[K-1].lower() s[:K-1] s :K-1 K-1 K 1 s[K-1].lower() [K-1].lower [K-1] s K-1 K 1 lower s[K:] s K: K print(new) print new new = s[:K-1] + s[K-1].lower() + s[K:] s[:K-1] + s[K-1].lower() + s[K:] new N,K = map(int,input().split()) map(int,input().split()) N K = map(int,input().split()) map(int,input().split()) K s = input() input() s
N,K = map(int,input().split())
s = input()
new = s[:K-1] + s[K-1].lower() + s[K:]
print(new)