8.2. kombinacii ot bykvi

using System;

public class Program
{
    public static void Main()
    {
        char start = char.Parse(Console.ReadLine());
        char end = char.Parse(Console.ReadLine());
        char drop = char.Parse(Console.ReadLine());
        int count = 0;
        for(char s1 = start; s1 <= end; s1++)
        {
            for(char s2 = start; s2 <= end; s2++)
            {
                for(char s3 = start; s3 <= end; s3++)
                {
                    if(s1 !=drop && s2 != drop && s3 != drop)
                    {
                    Console.Write("{0}{1}{2} ",s1,s2,s3);
                    count++;
                    }
                }
            }
        }
        Console.WriteLine(count);
    }
}