using System;

public class Program
{
    public static void Main()
    {
        //int num = int.Parse(Console.ReadLine() ?? string.Empty);
        string[] str = (Console.ReadLine() ?? string.Empty).Trim().Split(' ');
        //string str = Console.ReadLine() ?? string.Empty;
        

        int a = int.Parse(str[0]);
        int b = int.Parse(str[1]);

        Console.WriteLine(b-a);

    }
}