01. Numbers 1...N with Step 3

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

namespace Numbers1ToNWithStep3
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());

            for(int p=1;p<=n;p+=3)
                Console.WriteLine(p);
        }
    }
}