N,K=map(int,input().split())
a=input()
b=list(a)

c=b[K-1]
b[K-1]=c.lower()
print(''.join(map(str,b))) N,K=map(int,input().split()) N map(int,input().split()) map int input().split() ().split () input split K a=input() a input() input b=list(a) b list(a) list a c=b[K-1] c b[K-1] b K-1 K 1 b[K-1]=c.lower() b[K-1] b K-1 K 1 c.lower() c.lower c lower print(''.join(map(str,b))) print ''.join(map(str,b)) ''.join '' join map(str,b) map str b K=map(int,input().split()) map(int,input().split()) K N,K=map(int,input().split()) map(int,input().split()) N a=input() input() a c=b[K-1] b[K-1] c b=list(a) list(a) b
N,K=map(int,input().split())
a=input()
b=list(a)

c=b[K-1]
b[K-1]=c.lower()
print(''.join(map(str,b)))