#include<stdio.h>
int main()
{
    long long q1, p1, q2, p2, q3, p3;
    if(scanf("%lld %lld", &q1, &p1) != 2 ||scanf("%lld %lld", &q2, &p2) != 2 ||scanf("%lld %lld", &q3, &p3) != 2)
    {
     printf("Invalid input");
     return 0;
     if (q1 < 0 || p1 < 0 ||
     q2 < 0 || p2 < 0||
     q3 < 0 || p3 < 0) {
         printf("Invalid input");
         return 0;
} 
long long total = q1 * p1 + q2 * p2 +q3 * p3;
printf("%lld", total);
 return 0;   
}