#include<bits/stdc++.h>
using namespace std;
 
template<typename T1, typename T2> istream& operator>>(istream& is, pair<T1,T2>& a){ return is >> a.first >> a.second; }
template<typename T1, typename T2> ostream& operator<<(ostream& os, pair<T1,T2>& a){ return os << a.first << " "<<a.second; }
template<typename T> istream& operator>>(istream& is, vector< T >& vc){ for(int i = 0; i < vc.size(); i++) is >> vc[i]; return is; }
template<typename T> ostream& operator<<(ostream& os, vector< T >& vc){ for(int i = 0; i < vc.size(); i++) os << vc[i] << endl; return os; }
 
#define ForEach(it,c) for(__typeof (c).begin() it = (c).begin(); it != (c).end(); it++)
#define ALL(v) (v).begin(), (v).end()
#define UNQ(s) { sort(ALL(s)); (s).erase( unique( ALL(s)), (s).end());}
#define fr first
#define sc second
 
typedef pair< int , int > Pi;
typedef pair< int , Pi > Pii;
 
typedef long long int64;
const int INF = 1 << 30;

int main(){
  int N;
  cin >> N;
  vector< int > A(N), B(N);
  cin >> A;
  cin >> B;

  int ret = INF;

  priority_queue< Pi, vector< Pi >, greater< Pi > > que;
  for(int i = 0; i < N; i++){ /* 最初に戦うモンスター */
    for(int j = 0; j < N; j++) que.push( Pi( A[j], 0));

    int res = 0;
    int cnt = 0;
    while(!que.empty()) {
      int pos = (i + cnt) % N;

      Pi p = que.top(); que.pop(); /* 一番低いモンスター */
      int next_Cost = p.first + B[pos] / 2;
      res = max( res, p.second + 1); 
      que.push( Pi( next_Cost, p.second + 1));
      ++cnt;
    }
    ret = min( ret, res);
  }
  cout << ret << endl;
}