class Program
{
    static void Main(string[] args)
    {
        string[] input = Console.ReadLine()!.Split(' ');
        int vegetable = int.Parse(input[0]);
        int meat = int.Parse(input[1]);
        int multiple = int.Parse(input[2]);
        int max = int.Parse(input[3]);

        for (int i = 0; i <= vegetable; i++)
        {
            if ((i + 1) * multiple > meat || (i + 1) * multiple + (i + 1) > max)
            {
                Console.WriteLine(i);
                return;
            }
        }

        Console.WriteLine(vegetable);
    }
}