#include<bits/stdc++.h> using namespace std; int main(){ int n,FAL[1000],AK[1000],a,c=0; cin>>n; for(int i=0;i<=n-1;i++){ cin>>FAL[i]; } for(int i=0;i<=n-1;i++){ cin>>AK[i]; a=FAL[i]*AK[i]; c=c+a; } cout<<c; return 0; }