the type or namespace cannot be found

Hello

 using UnityEngine;
 using System.Collections.Generic;
 using System.Collections;
 
 public class newgame : MonoBehaviour {
       
     // creates a random degree for each planet
     public int degreegenerator ()
         {
             int generateddegree;
             generateddegree = Random.Range (0, 30);
             return generateddegree;
         }
           
     // creates a random element for each planet
     public string elementgenerator()
         {
             Dictionary<int, string> elementdictionary = new Dictionary<int, string>()
             {{1, "fire"}, {2, "earth"}, {3, "air"}, {4, "water"}};
 
             int elementnumber = Random.Range(1, 5);
 
             return elementdictionary[elementnumber];
         }
 
     // creates a random mode for each planet
     public string modegenerator ()
         {
             string[] modes = { "cardinal", "fixed", "mutable" };
 
             string mode = modes [Random.Range (0, modes.Length)];
             return mode;
         }
 
     // placing the generated mode, degree, element in planet
     class planet
     {
         elementgenerator planetelement = new elementgenerator ();
         degreegenerator planetdegree = new degreegenerator ();
         modegenerator planetmode = new modegenerator ();
     }
       
     // adding different planets into a list
     void planetgen ()
     {
         List<planet> planetslist = new List<planet>();
 
         planet sun = new planet ();
         planetslist.Add (sun);
         planet moon = new planet ();
         planetslist.Add (moon);
         planet mercury = new planet ();
         planetslist.Add (mercury);
         planet venus = new planet ();
         planetslist.Add (venus);
         planet mars = new planet ();
         planetslist.Add (mars);
         planet jupiter = new planet ();
         planetslist.Add (jupiter);
         planet saturn = new planet ();
         planetslist.Add (saturn);
     }
 }

Monodevelop says: The type or namespace name 'elementgenerator' could not be found. The type or namespace name 'modegenerator' could not be found. The type or namespace name 'degreegenerator' could not be found.

below code is the problem.

 class planet
     {
         elementgenerator planetelement = new elementgenerator ();
         degreegenerator planetdegree = new degreegenerator ();
         modegenerator planetmode = new modegenerator ();
     }

Please help me thanks:(