(재연습)구구단&2중 for문 구구단

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

namespace Study0121
{
    class Program
    {
        
        static void Main(string[] args)
        {
            int dan = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("{0}단", dan);
            for(int i = 0; i<9; i++)
            {
                int num = i + 1;
                int result = dan * num;
                Console.WriteLine("{0}X{1}={2}", dan, num, result);
            }
        }
    }
}

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

namespace Study0121
{
    class Program
    {
        
        static void Main(string[] args)
        {
            for(int i= 0; i<9; i++)
            {
                int dan = i + 1;
                if (dan > 1)
                {
                    for (int j = 0; j < 9; j++)
                    {
                        int num = j + 1;
                        int result = dan * num;
                        Console.WriteLine("{0}X{1}={2}", dan, num, result);
                    }
                }
                Console.WriteLine();
            }
            
        }
    }
}