Цикл

using System;
using System.Collections.Generic;
using System.Text;

namespace HELLOWORLD
{
    class Program
    {
        static void Main(string[] args)
        {
            int raz = 0;
           while (raz<100)
            {
                Console.WriteLine(raz);
                raz = raz + 1;
              
            }
            Console.ReadLine();


        }
    }
}