using System;

public class Program

{

    public static void Main()

    {

        int y;

        y = Factorial(10);

        Console.WriteLine("y={0}", y);

    }

    public static int ADD(int a, int b)

    {

        int c = a + b;

        return c;

    }

        public static int Multi(int a, int b)

        {

            int c = a *b;

            return c;

        }

        public static int Function(int x)

        {

            int y= Multi(2,x);

            y= y + 4;

            return y;

        }

        public static int Pow(int x, int i)

        {

            int r = x;

            while (i > 1)

            {

                x = x * r;

                i = i -1;

            }

            return x;

        }

        public static int Factorial(int x)

        {

            int i = x -1;

            while (i> 0)

            {

                x = x * i;

                i = i -1;

            }

            return x;

        }

}