public static void Main(String[] args)
int firstnum, secondnum, thirdnum;
Console.WriteLine("input first number");
firstnum = int.Parse(Console.ReadLine());
Console.WriteLine("input second number");
secondnum = int.Parse(Console.ReadLine());
Console.WriteLine("input third number");
thirdnum = int.Parse(Console.ReadLine());
Console.WriteLine("Expected Output: "+ firstnum * secondnum * thirdnum);