public static void Main()
Console.WriteLine("Enter first number:");
int num1 = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Enter last number:");
int num2 = Convert.ToInt32(Console.ReadLine());
Console.Write("last number must be larger than first number, please enter again: ");
num2 = Convert.ToInt32(Console.ReadLine());
Console.Write("Enter factor:");
int num = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("The multiply of " + num + " between " + num1 + " and " + num2 + " are :");