import java.lang.Math;

import java.util.Scanner;

public class CodeForces_403_B {

    private static final int N = (int) 6e4 + 10;

    static int a[] = new int[N];

    static int v[] = new int[N];

    static double eps = 1e-6;

    public static void main(String args[]) {

        // System.out.println("dfwaed");

        Scanner sc = new Scanner(System.in);

        while (sc.hasNext()) {

            int n = sc.nextInt();

            for (int i = 0; i < n; i++)

                a[i] = sc.nextInt();

            for (int i = 0; i < n; i++)

                v[i] = sc.nextInt();

            double l = 1, r = Double.MAX_VALUE, tmp = 0, tmp1, ans = 0;

            int tmp2 = 0;

            while (Math.abs(r - l) > eps) {

                double mid = (l + r) / 2;

                tmp = Double.MIN_VALUE;

                for (int i = 0; i < n; i++) {

                    tmp1 = Math.abs(a[i] - mid) / v[i];

                    if (tmp1 > tmp) {

                        tmp = tmp1;

                        tmp2 = i;

                    }

                }

                if ((double) a[tmp2] > mid) {

                    l = mid;

                    ans = tmp;

                } else

                    r = mid;

            }

            System.out.printf("%.6f\n", ans);

        }

        sc.close();

    }

}