using System;
using System.Collections.Generic;
using System.Linq;

namespace lv1_804
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] input = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            int a = input[0], b = input[1], c = input[2], d = input[3];

            var lst = new List<int>() { a, b / c, d / (c + 1) };
            Console.WriteLine(lst.Min());
        }
    }
}