#include <bits/stdc++.h>
#define int long long
#define uint unsigned int
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = (n); i >= 0; --i)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORR(i, a, b) for (int i = (a); i >= (b); --i)
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define SZ(a) ((int)(a).size())
#define PB(a) push_back(a)
#define EMP emplace
#define EMPB(...) emplace_back(__VA_ARGS__)
#define MP(a, b) make_pair(a, b)
#define MT(...) make_tuple(__VA_ARGS__)
#define Bit(n) (1LL << (n))
using namespace std;
using pii = pair<int, int>;
template <class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template <class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
const int MOD = 1000000007;
const int INF = 1LL << 30;
const double EPS = 1e-10;

int N;
int A[1510], B[1510];

int calc(int x) {
  priority_queue<pii, vector<pii>, greater<pii>> que;
  REP(i, N) que.EMP(A[i], 0);
  int r = 0;
  for (int i = x; ; i=(i+1)%N) {
    pii p = que.top(); que.pop();
    que.EMP(p.first+B[i]/2, p.second+1);
    chmax(r, p.second+1);
    if ((i+1)%N == x) break;
  }
  return r;
}

signed main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  
  cin >> N;
  REP(i, N) cin >> A[i];
  REP(i, N) cin >> B[i];
  int ans = INF;
  REP(i, N) {
    chmin(ans, calc(i));
  }
  cout << ans << endl;

  return 0;
}