#include<bits/stdc++.h>
using namespace std;
int main(){
	int a,b,c;
	float s;
	cin>>a>>b>>c;
	s=a*0.2+b*0.3+c*0.5;
	printf("%.0f",s);
}
/**************************************************************
	Problem: 1565
	User: toughuatao1
	Language: C++
	Result: Accepted
	Time:30 ms
	Memory:2072 kb
****************************************************************/