#include <algorithm>
#include <cmath>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <cassert>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define RSORT(c) sort((c).rbegin(),(c).rend())
#define CLR(a) memset((a), 0 ,sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

int main() {
    int n;
    cin >> n;
    vi friends(n), enemies(n);
    REP(i, n) cin >> friends[i];
    REP(i, n) cin >> enemies[i];

    int res = 10000;
    REP(i, n) {
        // level, cnt
        priority_queue<pii, vector<pii>, greater<pii>> que;
        REP(j, n) que.push({friends[j], 0});
        int ma = 0;
        FOR(j, i, i+n) {
            pii p = que.top(); que.pop();
            ma = max(ma, p.second + 1);
            que.push({p.first + enemies[j%n] / 2, p.second + 1});
        }
        res = min(res, ma);
    }
    cout << res << endl;
}