using System;

namespace Task373
{
    class Program
    {
        static void Main(string[] args)
        {
            // 1.
            int[] array = new int[70];
            GenerateRandomNumbers(array, 0, 201);
            PrintNotZero(array);

            // 2. 
            int[] arrayMul = new int[10];
            InputIntArray(arrayMul);
            Console.WriteLine(MultInInterval(arrayMul, 10, 20));

            // 3.
            Console.Write("Please, enter integer unsigned a = ");
            byte a = byte.Parse(Console.ReadLine());

            Console.Write("Please, enter integer unsigned b = ");
            byte b = byte.Parse(Console.ReadLine());

            Console.Write("Please, enter integer unsigned c = ");
            byte c = byte.Parse(Console.ReadLine());

            // Console.WriteLine(Sum(a) + Sum(b)*Sum(c));

            Console.WriteLine(Sum(a) + Sum(b*c));


            int number = 874;
            int firstDigit = number / 100;
            Console.Write(PrintTextDigit(firstDigit) + "стотин");

            int secondDigit = (number % 100) / 10;
            Console.Write(" " + PrintTextDigit(secondDigit) + "десет");

            int thirdDigit = number % 10;
            Console.Write(" и " + PrintTextDigit(thirdDigit));

            // Sum the add numbers for end type 0
            //int input = 0;
            //int sum = 0;
            //do
            //{
            //    Console.Write("Please, enter the next number (type 0 for end): ");
            //    input = int.Parse(Console.ReadLine());
            //    if (input % 2 == 1)
            //    {
            //        sum += input;
            //    }

            //} while (input != 0);

            //Console.WriteLine(sum);

        }

        public static void GenerateRandomNumbers(int[] array, int min, int max)
        {
            Random randomGen = new Random();
            for (int i = 0; i < array.Length; i++)
            {
                array[i] = randomGen.Next(min, max);
            }
        }

        public static void PrintNotZero(int[] array)
        {
            for (int i = 0; i < array.Length; i++)
            {
                if (array[i] != 0) Console.WriteLine("arra[{0}] = {1}", i, array[i]);
            }
        }

        public static void InputIntArray(int[] array)
        {
            for (int i = 0; i < array.Length; i++)
            {
                Console.Write("Please, eneter array[{0}] = ", i);
                array[i] = int.Parse(Console.ReadLine());
            }
        }

        public static int MultInInterval(int[] array, int min, int max) 
        {
            int mul = 1;
            for (int i = 0; i < array.Length; i++)
            {
                if (array[i] >= min && array[i] <= max)
                {
                    mul *= array[i];
                }
            }
            return mul;
        }

        public static ulong Sum(byte k)
        {
            int[] array = new int[k];
            Random randGen = new Random();
            ulong sum = 0;
            for (int i = 0; i < array.Length; i++)
            {
                array[i] = randGen.Next();
                if (array[i] % 2 == 0)
                {
                    sum += (ulong)array[i];
                }
            }
            return sum;
        }

        public static string PrintTextDigit(int digit)
        {
            switch (digit)
            {
                case 0:
                    return "Нула";
                case 1:
                    return "Едно";
                    break;
                case 2:
                    return  "Две";
                    break;
                case 3:
                    return  "Три";
                    break;
                case 4:
                    return  "Четири";
                    break;
                case 5:
                    return  "Пет";
                    break;
                case 6:
                    return "Шест";
                    break;
                case 7:
                    return "Седем";
                    break;
                case 8:
                    return "Осем";
                    break;
                case 9:
                    return "Девет";
                    break;
                default:
                    return "";
            }
        }


        // Sum of a sequence of math expressions
        public static double CalcMultiplication(int n)
        {
            double sum = 0;
            for (int i = 2; i <= n; i++)
            {
                sum += 1 / (Math.Pow(i,2) - (i-1) + 1);
            }
            return sum;
        }

        // Generate random numbers find mul of only 2 digit numbers the last digit 5
        public static int Sss(int k)
        {
            int mul = 1;
            Random randomGen = new Random();
            int[] array = new int[k];
            for (int i = 0; i < array.Length; i++)
            {
                array[i] = randomGen.Next();
                if (array[i] > 9 && array[i] < 100 && array[i] % 10 == 5)
                {
                    mul *= array[i];
                }
            }
            return mul;
        }


    }
}