#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
#define pb push_back
#define all(a) a.begin(), a.end()
#define sz(a) ((int)a.size())
#ifdef Doludu
template <typename T>
ostream& operator << (ostream &o, vector <T> vec) {
    o << "{"; int f = 0;
    for (T i : vec) o << (f++ ? " " : "") << i;
    return o << "}";
}
void bug__(int c, auto ...a) {
    cerr << "\e[1;" << c << "m";
    (..., (cerr << a << " "));
    cerr << "\e[0m" << endl;
}
#define bug_(c, x...) bug__(c, __LINE__, "[" + string(#x) + "]", x)
#define bug(x...) bug_(32, x)
#define bugv(x...) bug_(36, vector(x))
#define safe bug_(33, "safe")
#else
#define bug(x...) void(0)
#define bugv(x...) void(0)
#define safe void(0)
#endif
const int mod = 998244353, N = 1000005;

int main() {
    ios::sync_with_stdio(false), cin.tie(0);
    int n;
    cin >> n;
    vector <int> a(n), b(n);
    for (int i = 0; i < n; ++i) cin >> a[i];
    for (int i = 0; i < n; ++i) cin >> b[i];
    
    double l = 0, r = 1e18;
    for (int iter = 0; iter < 200; ++iter) {
        double m = (l + r) / 2;
        m = 1;
        vector <double> c(n);
        for (int i = 0; i < n; ++i) {
            c[i] = a[i] - b[i] * m;
        }
        vector <double> pre(n + 1);
        for (int i = 1; i <= n; ++i) pre[i] = pre[i - 1] + c[i - 1];
        int ptr = 0;
        double mn = 0;
        for (int i = 1; i <= n; ++i) {
            if (mn <= pre[i]) {
                for (int j = ptr; j <= i; ++j) {
                    mn = min(mn, pre[j]);
                }
                ptr = i;
            }
        }
        if (ptr == n) l = m;
        else r = m;
        break;
    };

    cout << fixed << setprecision(15) << l << "\n";
}