#include <iostream>
#include <cstdio>
using namespace std;
int main()
{
    int num1,num2;
    double a1,b1,a2,b2;
    cin >>num1>>a1>>b1>>num2>>a2>>b2;
    printf ("VALOR A PAGAR: R$ %.2f", a1* b1 + a2*b2);
    return 0;
}