using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        if (c[0] >= c[1])
        {
            WriteLine(c[1] + (c[0] - c[1]) / (c[2] + 1));
        }
        else
        {
            WriteLine(c[0] + (c[1] - c[0]) / (c[3] + 1));
        }
    }
}