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

#define REP(i,s,e) for (i = s; i <= e; i++)
#define rep(i,n) REP (i,0,(int)(n)-1)
#define RREP(i,s,e) for (i = s; i >= e; i--)
#define rrep(i,n) RREP (i,(int)(n)-1,0)
#define INF (int)1e8
#define MOD (int)(1e9+7)

typedef long long ll;

int main(void) {
    int i, n;
    int a[1500], b[1500];
    cin >> n;
    rep (i,n) cin >> a[i];
    rep (i,n) cin >> b[i];

    int s, ans = INF;
    rep (s,n) {
        int count = 0;
        priority_queue<pair<int,int>> q; // (-level,-count)
        rep (i,n) q.push(make_pair(-a[i],0));
        rep (i,n) {
            auto p = q.top();
            q.pop();
            p.first -= b[(s+i)%n]/2;
            p.second--;
            count = max(count,-p.second);
            q.push(p);
        }
        ans = min(count,ans);
    }
    cout << ans << endl;
    return 0;
}