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