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