#include <bits/stdc++.h>
using namespace std;
int main(){
  cin.tie(nullptr)->sync_with_stdio(false);
  using P = pair<int, int>;
  int N; cin >> N;
  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 = 1e9;
  for(int i = 0; i < N; ++i){
    priority_queue<P, vector<P>, greater<P>> que;
    for(int j = 0; j < N; ++j){
      que.emplace(A[j], 0);
    }

    int res = 0;
    for(int j = 0; j < N; ++j){
      const auto [cur_health, fight_till_now] = que.top();
      que.pop();
      res = max(res, fight_till_now + 1);
      que.emplace(cur_health + B[(i + j) % N] / 2, fight_till_now + 1);
    }
    ret = min(ret, res);
  }
  cout << ret << endl;
  return 0;
}