#include<cstdio>
#include<iostream>

using namespace std;

int main()
{
    int a,b,c,d;
    double h,i;
    cin >> a >> b >>h;
    cin >> c >> d >>i;
    double sum;
    sum=b*h+d*i;
    printf("VALOR A PAGAR: R$ %.2lf",sum);

    return 0;
}