#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() using namespace std; int main(){ int n,s=0; cin>>n; int a[n],b[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++){ s+=b[i]*a[i] ; } cout<<s; return 0; }