#include<stdio.h>
int main()
{
    int a,b,c,x,y,z,total_cost;
    scanf("%d%d",&a,&x);
    scanf("%d%d",&b,&y);
    scanf("%d%d",&c,&z);
    total_cost=(a*x)+(b*y)=(c*z);
    if(a<=0||b<=0||c<=0||x<=0||y<=0||z<=0)
    {
        printf("Invalid input\n");
    }
    else
    {
        printf("%d|n",total_cost);
    }
    return 0;
}