//In Forest.cs file 
using System;

namespace BasicClasses
{
  class Forest
  {
    //No need the field for name and trees since using automatic property 
    public int age;
    public string biome;
    
    public string Name
    {
      get; set;  //No need to define as a hidden field is defined in the background for us
    }
    
    public int Trees
    {
      get; set; 
    }
    
    public string Biome
    {
      get { return biome; }
      set
      {
        if (value == "Tropical" || value == "Temperate" || value == "Boreal")
        {
          biome = value;
        }
        else
        {
          biome = "Unknown";
        }
      }
    }
  }
}

//Program.cs file remains the same