#include<stdio.h>
int main()
{
    int qx, px;
    int qy, py;
    int qz, pz;
    (scanf("%d %d", &qx, &px) != 2)   {
        printf("Invalid input");
    }
    (scanf("%d %d", &qy, py) != 2)
    {
        printf("Invalid input");
    }
    (scanf("%d %d", &qz, pz) != 2)
    {
        printf("Invalid input");
    }
    if (qx < 0 || px < 0 || qy < 0 || py < 0 ||qz < 0 || pz < 0)
    {
        printf("Invalid input");
    }
    int total = (qx * px) + (qy * py) + (qz + pz);
      printf("%d", Total);
    return 0;
}