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