#include <bits/stdc++.h> using namespace std; long long n, a[1000005], b, sum; int main() { //freopen("algebra.in", "r", stdin); //freopen("algebra.out", "w", stdout);//文件操作 cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i]; } for (int i = 1; i <= n; i++) { cin >> b; sum += a[i] * b; } cout << sum; return 0; }