using System;
using System.Collections.Generic;
class Program
    {
    	static void Main(string[] args)
    	{
    		string[] s = Console.ReadLine().Split(' ');
            int a = int.Parse(s[0]);
            int b = int.Parse(s[1]);
            int c = int.Parse(s[2]);
            int d = int.Parse(s[3]);
            int ans = 0;
            while(d >= c + 1)
            {
                if(a < 1 || b < c) break;
                a--;
                b -= c;
                ans++;
                d -= c + 1;
            }
            Console.WriteLine(ans);
            
        }
    }
    //mcs Main.cs
    //mono Main.exe