#include <bits/stdc++.h>

using namespace std;

const int INF = 1<<20;

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;
  vector<int> a(n), b(n);
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 0; i < n; i++) cin >> b[i];

  int ret = INF;
  for (int k = 0; k < n; k++) {
    priority_queue<tuple<int, int>, vector<tuple<int, int>>, greater<tuple<int, int>> > q;
    for (int i = 0; i < n; i++)
      q.emplace(a[i], 0);

    int tmp = 0;
    for (int i = 0; i < n; i++) {
      int j = (k + i) % n;
      int lv, cnt;
      tie(lv, cnt) = q.top();
      q.pop();
      ++cnt;
      tmp = max(tmp, cnt);
      q.emplace(lv + b[j] / 2, cnt);
    }

    ret = min(ret, tmp);
  }
  cout << ret << endl;
  
  return 0;
}