#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a,b,c;
	cin>>a>>b>>c;
	int z;
	z=a*0.2+b*0.3+c*0.5;
	cout<<z;


	return 0;
}

/**************************************************************
	Problem: 1565
	User: 21A
	Language: C++
	Result: Accepted
	Time:25 ms
	Memory:2072 kb
****************************************************************/