#include <iostream>
#include <set>
using namespace std;

#ifndef INT_MAX
#define INT_MAX 0x7FFFFFFF
#endif

#define N 1500

int n;
int units[N];
int monsters[N];

int battle(int i)
{
	multiset<unsigned int> unit_infos;
	for ( int j = 0; j < n; j++ ) {
		unit_infos.insert(units[j] << 16);
	}

	int max = 0;
	for ( int j = 0; j < n; j++ ) {
		int k = (i + j) % n;
		auto unit = unit_infos.begin();
		auto info = *unit;
		info = info + ((monsters[k] / 2) << 16) + 1;
		unit_infos.erase(unit);
		unit_infos.insert(info);
		max = max < (int)(info & 0xFFFF) ? (info & 0xFFFF) : max;
	}

	return max;
}

int main()
{
	cin >> n;
	for ( int i = 0; i < n; i++ ) {
		cin >> units[i];
	}
	for ( int i = 0; i < n; i++ ) {
		cin >> monsters[i];
	}

	int min = INT_MAX;
	for ( int i = 0; i < n; i++ ) {
		int t = battle(i);
		min = t < min ? t : min;
	}

	cout << min << endl;

	return 0;
}