#include <bits/stdc++.h>
using namespace std;

int main() {
	int w, z;
	string bs;
	cin >> w >> z >> bs;
	int b = (bs[0] - '0') * 10 + bs[2] - '0' + 10;
	int ans = (w + z) * b / 10;
	cout << ans << endl;
}