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