n,k = map(int,input().split())
s = input()
s = s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) + s[k:]
print(s) n,k = map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split k s = input() s input() input s = s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) + s[k:] s s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) + s[k:] s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) s[:k-1] s :k-1 k-1 k 1 chr(ord(s[k-1])+ord('a')-ord('A')) chr ord(s[k-1])+ord('a')-ord('A') ord(s[k-1])+ord('a') ord(s[k-1]) ord s[k-1] s k-1 k 1 ord('a') ord 'a' ord('A') ord 'A' s[k:] s k: k print(s) print s n,k = map(int,input().split()) map(int,input().split()) n s = input() input() s s = s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) + s[k:] s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) + s[k:] s k = map(int,input().split()) map(int,input().split()) k
n,k = map(int,input().split())
s = input()
s = s[:k-1] + chr(ord(s[k-1])+ord('a')-ord('A')) + s[k:]
print(s)
