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

tmp =s[k-1].lower()

s = s[0:k-1] + tmp + s[k:]

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 tmp =s[k-1].lower() tmp s[k-1].lower() [k-1].lower [k-1] s k-1 k 1 lower s = s[0:k-1] + tmp + s[k:] s s[0:k-1] + tmp + s[k:] s[0:k-1] + tmp s[0:k-1] s 0:k-1 0 k-1 k 1 tmp s[k:] s k: k print(s) print s s = s[0:k-1] + tmp + s[k:] s[0:k-1] + tmp + s[k:] s k = map(int,input().split()) map(int,input().split()) k tmp =s[k-1].lower() s[k-1].lower() tmp s = input() input() s n,k = map(int,input().split()) map(int,input().split()) n

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

tmp =s[k-1].lower()

s = s[0:k-1] + tmp + s[k:]

print(s)