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

if s[k - 1] == 'A':
    s[k - 1] = 'a'
if s[k - 1] == 'B':
    s[k - 1] = 'b'
if s[k - 1] == 'C':
    s[k - 1] = 'c'
strA = ''.join(s)
print(strA) 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 if s[k - 1] == 'A':
    s[k - 1] = 'a' s[k - 1] == 'A' s[k - 1] s k - 1 k 1 'A' s[k - 1] = 'a' s[k - 1] s k - 1 k 1 'a' if s[k - 1] == 'B':
    s[k - 1] = 'b' s[k - 1] == 'B' s[k - 1] s k - 1 k 1 'B' s[k - 1] = 'b' s[k - 1] s k - 1 k 1 'b' if s[k - 1] == 'C':
    s[k - 1] = 'c' s[k - 1] == 'C' s[k - 1] s k - 1 k 1 'C' s[k - 1] = 'c' s[k - 1] s k - 1 k 1 'c' strA = ''.join(s) strA ''.join(s) ''.join '' join s print(strA) print strA n,k = map(int,input().split()) map(int,input().split()) n strA = ''.join(s) ''.join(s) strA k = map(int,input().split()) map(int,input().split()) k s = list(input()) list(input()) s
n,k = map(int,input().split())
s = list(input())

if s[k - 1] == 'A':
    s[k - 1] = 'a'
if s[k - 1] == 'B':
    s[k - 1] = 'b'
if s[k - 1] == 'C':
    s[k - 1] = 'c'
strA = ''.join(s)
print(strA)