Returning object as parameter (pre-example without overloading), C#

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//Rextester.Program.Main is the entry point for your code. Don't change it.
//Compiler version 4.0.30319.17929 for Microsoft (R) .NET Framework 4.5

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;

namespace Rextester
{
    
    class Number
    {
      int n;
      public Number()
      {
          n=0;
      }
      public Number(int x)
      {
        n = x;
      }
      
      public Number add(Number y)
      {
          Number t=new Number();
          t.n = n+y.n;
          return t;
      }
        
      public int getValue()
      {
          return n;
      }
    }

public class Program
    {
        public static void Main(string[] args)
        {
            Number n1 = new Number(10);
            Number n2 = new Number(5);
            Number n3 = new Number();  // n3.n = 0
            
            n3 = n1.add(n2);
            Console.WriteLine("Number 1 : " + n1.getValue());
            Console.WriteLine("Number 2 : " + n2.getValue());
            Console.WriteLine("Addition : " + n3.getValue());
        }
    }
}

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