asd

#include <iostream>
#include <string>
using namespace std;
string asd(string a, char b, int c)
{
	for (int i = 0; i < a.size(); i++)
	{
		a[c-1] = b;
	}
	return a;
}
int main()
{
	string a;
	char b;
	int c;
	cin >> a >> b >> c;
	cout << asd(a, b, c);
}