#include <bits/stdc++.h>
using namespace std;
int main(){
	int A,B,C,F;
	cin>>A>>B>>C;
	F=A*0.2+(B*0.4)+C*0.5;
	printf("%d",F);
}
/**************************************************************
	Problem: 1565
	User: tonghuawei
	Language: C++
	Result: Wrong Answer
****************************************************************/