#include <iostream>
#include <queue>
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)
{
	priority_queue<unsigned int, vector<unsigned int>, greater<unsigned int>> q;
	for ( int j = 0; j < n; j++ ) {
		q.push(units[j] << 16);
	}

	int max = 0;
	for ( int j = 0; j < n; j++ ) {
		int k = (i + j) % n;
		auto unit = q.top();
		q.pop();
		unit = unit + ((monsters[k] / 2) << 16) + 1;
		q.push(unit);
		max = max < (int)(unit & 0xFFFF) ? (unit & 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;
}