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

namespace ExceptionFatorial
{
    class Program
    {
        public static int Fatorial(int n)
        {
            if (n < 0)
            {
                Exception e = new Exception("Nao pode ser negativo! ");
                throw e;
            }

            int fat = 1;
            for (int i = 2; i <= n; i++)
			{
			    fat = fat * i;
			}
            return fat;
        }
    }
}





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

namespace ExceptionFatorial
{
    class app
    {
        static void Main(string[] args)
        {
            Console.Write("Informe o valor de n: ");
            int n = Convert.ToInt32(Console.ReadLine());

            while (n != 0)
            {
                try
                {
                    Console.WriteLine("O fatorial de {0} é {1}", n, Program.Fatorial(n));
                }
                catch (Exception ex)
                {
                    Console.Write(ex.Message);

                }


                Console.Write("Informe o valor de n: ");
                n = Convert.ToInt32(Console.ReadLine());
            }
        }
    }
}