#include<bits/stdc++.h> using namespace std; int main (){ int n,sum = 0; cin >> n; int a[1001],b[1001]; for(int i = 1;i <= n;i++) { cin >> a[i]; } for(int i = 1;i <= n;i++) { cin >> b[i]; } for(int i = 1;i <= n;i++) { sum = sum + a[i] * b[i]; } cout << sum; return 0; }