n, k = map(int, input().split())
s = list(input())

s[k-1] = s[k-1].swapcase()
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] = s[k-1].swapcase() s[k-1] s k-1 k 1 s[k-1].swapcase() [k-1].swapcase [k-1] s k-1 k 1 swapcase 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] = s[k-1].swapcase()
print("".join(s))