#include<stdio.h>
int calculateTotal(int qA, int pA, int qB, int pB, int qC, int pC)
{
    return (qA*pA) + (qB*pB) + (qC*pC);
}
int main()
{
    int qA,pA,qB,pB,qC,pC;
    scanf("%d %d",&qA,&pA);
    scanf("%d %d",&qB,&pB);
    scanf("%d %d",&qC,&pC);
    if(qA<0 || pA<0 || qB<0 || pB<0 || qC<0 || pC<0)
    {
        priintf("Invalid input");
        return 0;
    }
    int total = calculateTotal(qA,pA,qB,pB,qC,pC);
    printf("%d", total);
    return 0;
}