#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

struct ST {
  ll level;
  ll num;
};
bool operator<(const ST& a, const ST& b){
  if(a.level == b.level) return a.num > b.num;
  return a.level > b.level;
}

int main(){
  int N;
  deque<ll> A, B;
  ll a, b, ret = 1000000000LL;
  
  cin >> N;
  rep(i,N){
    cin >> a;
    A.push_back(a);
  }
  rep(i,N){
    cin >> b;
    B.push_back(b);
  }

  rep(i,N){
    priority_queue<ST> que;
    rep(j,N){
      ST st;
      st.level = A[j];
      st.num = 0;
      que.push(st);
    }
    
    rep(j,N){
      ST st = que.top(); que.pop();
      ll enm = B[(i+j)%N];
      st.level += enm/2;
      st.num++;
      que.push(st);
    }
    ll mx = 0;
    while(!que.empty()){
      ST st = que.top(); que.pop();
      mx = max(mx, st.num);
    }
    ret = min(ret, mx);
  }

  cout << ret << endl;
  return 0;
}