#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int N;
int A[1500];
int B[3000];

int main() {
    cin >> N;
    rep(i, N) cin >> A[i];
    rep(i, N) cin >> B[i]; rep(i, N) B[i + N] = B[i] = B[i] / 2;

    int ans = N;
    rep(s, N) {
        priority_queue<pair<int, int>> Q;
        rep(i, N) Q.push({ -A[i], 0 });
        rep(i, N) {
            auto p = Q.top(); Q.pop();
            p.second--;
            p.first -= B[s + i];
            Q.push(p);
        }
        int tmp = 0;
        while (Q.size()) { tmp = max(tmp, -Q.top().second); Q.pop(); }
        ans = min(ans, tmp);
    }

    cout << ans << endl;

    return 0;
}