#include <bits/stdc++.h>
using namespace std;    
typedef long long ll;
typedef pair<int,int> pii;
#define rep(i,n) for(int i=0;i<(n);i++)
int n,a[3010],b[3010],ans=1e9;
priority_queue<pii> pq;
int main() {
    cin>>n;
    for (int i=1;i<=n;++i) cin>>a[i],a[n+i]=a[i];
    for (int i=1;i<=n;++i) cin>>b[i],b[n+i]=b[i];
    for (int i=1;i<=n;++i) {
        for (int j=1;j<=n;++j) pq.push(make_pair(-a[j],0));
        for (int j=i;j<i+n;++j) {
            pii p=pq.top(); pq.pop();
            p.first-=b[j]/2;
            p.second-=1;
            pq.push(p);
        }
        int mx=0;
        while (!pq.empty()) {
            mx=max(mx,-pq.top().second); pq.pop();
        }
        if (mx<ans) ans=mx;
    }
    cout<<ans<<endl;
    return 0;
}