import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double a = sc.nextInt();
		double b = sc.nextInt();
		double c = sc.nextInt();
		int d = 0;
		d =(int)( a * 0.2 + b * 0.3 + c * 0.5);
		System.out.println(d);
		sc.close();
	}
}
/**************************************************************
	Problem: 1565
	User: admin
	Language: Java
	Result: Accepted
	Time:2446 ms
	Memory:40392 kb
****************************************************************/