#include<stdio.h>
int main()
{
    int qX,pX,qY,pY,qZ,pZ;
    
    if(scanf("%d%d", &qX,&pX) != 2)
    {
        printf("Invalid input\n");
        return 0;
    }
    if(scanf("%d%d", &qY,&pY) != 2)
    {
        printf("Invalid input\n");
        return 0;
    }
    if(scanf("%d%d", &qZ,&pZ) != 2)
    {
        printf("Invalid input\n");
        return 0;
    }
    if(qX,0 || pX<0 || qY<0 || pY<0 || qZ<0 || pZ<0)
    {
        printf("Invalid input\n");
        return 0;
    }
    long long Total Cost = (1LL*qX*pX) + (1LL*qY*pY) + (1LL*qZ*pZ);
    printf("%lld\n",Total Cost);
    return 0;
}