#include<bits/stdc++.h>
#define int long long
#define w first
#define f second
using namespace std;
int n,ans=0;
pair<int,int>arr[100000+10];
bool cmp(pair<int,int> a,pair<int,int> b){
    return a.w*b.f<b.w*a.f;
}
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin>>n;
    for(int i=0;i<n;i++)cin>>arr[i].w;
    for(int i=0;i<n;i++)cin>>arr[i].f;
    sort(arr,arr+n,cmp);
    int cnt=arr[0].w;
    for(int i=1;i<n;i++){
        ans+=arr[i].f*cnt;
        cnt+=arr[i].w;
    }
    cout<<ans;
}

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2 
20 10 
1 1