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