#include<stdio.h>
int main()
{
    int x,y,z,x1,y1,z1,total_cost;
    scanf ("%d%d",&x,&x1);
    scanf ("%d%d",&y,&y1);
    scanf ("%d%d",&z,&z1);
    total_cost=(a*x)+(b*y)+(c*z);
    if(x<=0&&y<=0&&z<=0&&x1<=0&&y1<=0&&z1<=0)
    {
        printf ("Invalid input\n");
    }
    else
    {
     printf ("%d\n",total_cost);   
    }
    return 0;
}