#include <iostream>
using namespace std;

int main() {
    int a, b, c;
    cin >> a >> b >> c;
    int result = a * 0.2 + b * 0.3 + c * 0.5;
    cout << result;
    return 0;
}
/**************************************************************
	Problem: 1565
	User: fuhoubin
	Language: C++
	Result: Accepted
	Time:42 ms
	Memory:2072 kb
****************************************************************/