#include <cmath>
#include <map>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>
#include <functional>
#include <iostream>
using namespace std;
#define repi(_I, _B, _E) for(int _I = (_B); (_I) < (_E); ++ (_I))
#define rep(_I, _N) for(int _I = 0; (_I) < (_N); ++ (_I))
#define all(_X) (_X).begin(), (_X).end()

int n;
vector<int> lvs;
#define mkp make_pair

int main() {
	cin >> n;

	priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> que, que_bak;
	rep(i, n) {
		int a;
		cin >> a;
		que.push(make_pair(a, 0));
	}
	rep(i, n) {
		int b; cin >> b;
		lvs.push_back(b / 2);
	}
	que_bak = que;

	int mi = 1<<29;
	rep(i, n) {
		int ma = 0;
		repi(j, i, i + n) {
			auto p = que.top(); que.pop();
			que.push(make_pair(p.first + lvs[j % n], p.second + 1));
			ma = max(ma, p.second + 1);
		}
		que = que_bak;

		mi = min(mi, ma);
	}
	cout << mi << endl;

	return 0;
}