#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main()
{
    int n;
    cin>>n;

    vector<pair<long long,long long>> a(n);
    for(auto &x:a)cin>>x.first;
    for(auto &x:a)cin>>x.second;
    sort(a.begin(),a.end());
    int endi=n-1;
    int i=0;
    long long ans=0;
    long long level=0;
    while(i<=endi)
        {
        if(a[i].first<=level)
            {
            ans+=a[i].second;
            level+=a[i].second;

            i++;
            }
        else
            {
            int modosit=min(a[i].first-level,a[endi].second);
            ans+=modosit*2;
            level+=modosit;
            a[endi].second-=modosit;


            if(a[endi].second==0)
                endi--;
            }

        }
    cout<<ans;
    return 0;
}