using System;

public class Program

{

    public static void Main()

    {

​

                     Console.WriteLine("Digite o CPF:");

                     int cpf1 = Convert.ToInt32(Console.ReadLine());

                     if (cpf1 <= 10) {

                    Console.WriteLine("CPF INVALIDO");

                     } else (cpf1 => 11) ;

                    Console.WriteLine("CPF VALIDO");

                            }       

    }

​