#define REP(i,n) for(int i=0; i<(int)(n); i++)

#include <queue>
#include <cstdio>
inline int getInt(){ int s; scanf("%d", &s); return s; }

#include <set>

using namespace std;

int main(){
  const int n = getInt();
  vector<int> a(n);
  vector<int> b(n);

  REP(i,n) a[i] = getInt();
  REP(i,n) b[i] = getInt();

  int ans = n;
  REP(s,n){
    typedef pair<int, int> data;
    priority_queue<data, vector<data>, greater<data> > pq;
    REP(i,n) pq.push(make_pair(a[i], 0));

    REP(i,n){
      const data d = pq.top(); pq.pop();
      const int bb = b[(i + s) % n];
      pq.push(data(d.first + bb / 2, d.second + 1));
    }

    int tmp = 0;
    while(pq.size()){
      tmp = max(tmp, pq.top().second);
      pq.pop();
    }

    ans = min(ans, tmp);
  }

  printf("%d\n", ans);
  return 0;
}