n,k=map(int,input().split())
k-=1
s=input()
print(s[:k]+s[k].lower()+s[k+1:]) n,k=map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split k k-=1 k 1 s=input() s input() input print(s[:k]+s[k].lower()+s[k+1:]) print s[:k]+s[k].lower()+s[k+1:] s[:k]+s[k].lower() s[:k] s :k k s[k].lower() [k].lower [k] s k lower s[k+1:] s k+1: k+1 k 1 k=map(int,input().split()) map(int,input().split()) k k-=1 1 k n,k=map(int,input().split()) map(int,input().split()) n s=input() input() s
n,k=map(int,input().split())
k-=1
s=input()
print(s[:k]+s[k].lower()+s[k+1:])
