static void Main()
{
Console.WriteLine("Input a number");
int number = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input a second number (optional)");
string input = Console.ReadLine();
MathOperations math = new MathOperations();
if (input != "")
{
int number2 = Convert.ToInt32(input);
Console.WriteLine(math.Add(number, number2));
}
else
{
Console.WriteLine(math.Add(number));
}
Console.Read();
}