#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) repi(i,0,n)
#define repi(i,a,b) for(int i=int(a);i<int(b);++i)
#define long int64_t
#define ulong uint64_t

const int N = 1500;
int n, a[N], b[N];

void input()
{
    cin >> n;
    rep(i, n) cin >> a[i];
    rep(i, n) cin >> b[i];
}

struct monster
{
    int id, level, cnt;
    monster(int id, int level, int cnt = 0) : id(id), level(level), cnt(cnt) {}
    void fight(int t) { level += t / 2, ++cnt; }
    bool operator <(const monster& t) const {
        return level != t.level ? level > t.level : cnt > t.cnt;
    }
};

int simulate(int offset)
{
    int ret = 0;
    priority_queue<monster> q;
    rep(i, n) q.emplace(i, a[i]);
    rep(i, n) {
        auto cur = q.top();
        q.pop();

        cur.fight(b[(i + offset) % n]);
        ret = max(ret, cur.cnt);
        q.push(cur);
    }
    return ret;
}

int solve()
{
    int ans = int(1e9);
    rep(i, n) ans = min(ans, simulate(i));
    return ans;
}

int main()
{
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    input();
    cout << solve() << endl;
}