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