using System;

namespace PCNestedClass {

​

  public class Pc {

    public void displayPc() {

      Console.WriteLine("Pc: Microsoft Surface");

    }

    internal class Cpu {

      public void displayCpu() {

        Console.WriteLine("Cpu: Intel Core i7");

      }

    }

  }

  class Program {

    static void Main(string[] args) {

      Pc pcObj = new Pc(); // Try to comment this row

      pcObj.displayPc();   // Try to comment this row

      //pcObj.displayCpu();  // this code doesn't work

​

      Pc.Cpu cpuObj = new Pc.Cpu();

      cpuObj.displayCpu();

    }

  }

}