#include <iostream>
using namespace std;
int main()
{
    int n,printout;
    int a[n];
    int b[n];
    cin >> n;
    for(int i = 0;i <= n - 1;i++)
    {
        cin >> a[i];
    }
    for(int i = 0;i <= n - 1;i++)
    {
        cin >> b[i];
    }
    for(int i = 0;i <= n - 1;i++)
    {
        printout += a[i] * b[i];
    }
    cout << printout;
    return 0;
}