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