Practic 3.4

using System;

namespace Practice
{
    class Program1
    {
        static void Main(string[] args)
        {
            for (int i = 10; i < 100; ++i)
            {
                if (i % 10 != i / 10)
                {
                    Console.WriteLine($"{i}");
                }
            }
            Console.ReadKey();
        }
    }
}