using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

    public struct Cat : IEquatable<Cat>

    {

        public readonly string Name;

        public Cat(string name) {this.Name = name;}

        public bool Equals(Cat other)

        {

            return this.Name.Equals(other.Name);

        }

        public override bool Equals(object obj)

        {

            if (obj == null || obj.GetType() != this.GetType())

                return false;

            return this.Name.Equals(((Cat)obj).Name);

        }

        public override int GetHashCode()

        {

            return this.Name.GetHashCode();

        }

    }

}