using System;

​

namespace First

{

    public class Program

    {

        public static void Main(string[] args)

        {

            Console.WriteLine("Max(1, 2, 3) is 3: " + (Max(1, 2, 3) == 3));

            Console.WriteLine("Max(5, 6, 4) is 6: " + (Max(5, 6, 4) == 6));

            Console.WriteLine("Max(9, 4, 3) is 9: " + (Max(9, 4, 3) == 9));

            Console.WriteLine("Max(9, 9, 9) is 9: " + (Max(9, 9, 9) == 9));

            Console.WriteLine();

​

            Console.WriteLine("Factorial(1) is 1: " + (Factorial(1) == 1));

            Console.WriteLine("Factorial(5) is 120: " + (Factorial(5) == 120));

            Console.WriteLine();

​

            Console.WriteLine("First(4, 3, 1) is 59/6: " + (First(4, 3, 1) == 59.0 / 6.0));

            Console.WriteLine("First(5, 12, 3) is 43/2: " + (First(5, 12, 3) == 43.0 / 2.0));

            Console.WriteLine();

​

            Console.WriteLine("Second(4, 0) is 2: " + (Second(4, 0) == 2));

            Console.WriteLine("Second(2, 5) is 2.7002782... : " + (Second(2, 5) == Math.Sqrt(2 + Math.Sqrt(4 + 6 + 8 + 10))));

            Console.WriteLine();

        }

​

        static double Max(double a, double b, double c)

        {

            return (a > b) ? ((a > c) ? a : c) : ((b > c) ? b : c);

        }

​

        static int Factorial(int n)

        {

            if (n <= 1)

            {

                return 1;

            }

            return n * Factorial(n - 1);

        }

​

        // max(a, b, c) a = 2 * sqrt(x^2 + y^2) - z^3/3!; b = 1 - sqrt(x^2 + y^2); c = sin(z^3/3!) + cos(pi/4)

        static double First(double x, double y, double z)

        {

            double a = 2 * Math.Sqrt(x * x + y * y) - (z * z * z) / Factorial(3);

            double b = 1 - Math.Sqrt(x * x + y * y);

            double c = Math.Sin((z * z * z) / Factorial(3)) + Math.Cos(Math.PI / 4);

            return Max(a, b, c);

        }

​

        // sqrt(x + sqrt(2 * x + ... + n * x))

        static double Second(double x, int n)

        {

            double sum = 0;

            for (int i = 2; i <= n; i++)

            {

                sum += i * x;

            }

            return Math.Sqrt(x + Math.Sqrt(sum));

        }

    }

}

​