using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Carlos Ivan Lopez Aldava");

        int n,i,sum=0;

  int t=1;

    Console.Write("\n\n");

    Console.Write("Calculate the sum of the series 1 +11 + 111 + 1111 + .. n terms:\n");

    Console.Write("------------------------------------------------------------------");

    Console.Write("\n\n");    

  Console.Write("Input the numbe of terms : ");

   n= Convert.ToInt32(Console.ReadLine());  

  for(i=1;i<=n;i++)

  {

     Console.Write("{0} + ",t);

     sum=sum+t;

     t=(t*10)+1;

  }

  Console.Write("\nThe Sum is : {0}\n",sum);

    }

}