using System;

public class Program

{

    public static void Main()

    {

        int a,b,c,d;

        a = int.Parse(Console.ReadLine());

        b = int.Parse(Console.ReadLine());

        c = int.Parse(Console.ReadLine());

        a = a*1000;

        b = b-c;

        d = a/b;

        Console.WriteLine(d);

    }

}