#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int n,sum=0; cin>>n; int a[n]={},b[n]={}; for(int i=0;i<n;i++){ cin>>a[i];} for(int i=0;i<n;i++){ cin>>b[i]; sum+=a[i]*b[i]; } cout<<sum; return 0; }