LettersCombinations

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

namespace NestedLoopsDemo
{
    class LettersCombinations
    {
        static void Main(string[] args)
        {
            char startChar = char.Parse(Console.ReadLine());
            char endChar = char.Parse(Console.ReadLine());
            char bannedChar = char.Parse(Console.ReadLine());

            int printCount = 0;
            for (char i = startChar; i <= endChar; i++)
            {
                for (char j = startChar; j <= endChar; j++)
                {
                    for (char k = startChar; k <= endChar; k++)
                    {
                        bool wordIsValid = i != bannedChar &&
                                           j != bannedChar &&
                                           k != bannedChar;

                        if (!wordIsValid)
                        {
                            continue;
                        }

                        Console.Write($"{i}{j}{k} ");
                        printCount++;
                    }
                }
            }

            Console.WriteLine(printCount);
        }
    }
}