Triangle With Different Size (Nakov)

using System;

namespace ConsoleApp4
{
    public class Triangle
    {
        public static void PrintLine(int start,int end)
        {
            for (int i = start; i <= end; i++)
            {
                Console.Write(i + " ");
            }
            Console.WriteLine();
        }
        public static void WritingLine(int n)
        {
            for (int i = 1; i <= n; i++)
            {
                PrintLine(1, i);
            }
            for (int i = n-1; i >=1; i--)
            {
                PrintLine(1, i);
            }
        }
    }

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