task 2

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Please enter a whole number");
            int num = Convert.ToInt32(Console.ReadLine());
            for (int i = 1; i <= num; i++)
            {
                if (((i % 3) != 0) || (i % 7) != 0)
                {
                    Console.WriteLine(i);
                }
            else
            {
                    Console.WriteLine("Invalid Input!");
                }
            }
        }
    }
}