import cs1.Keyboard;

public class Sum_even
{
	public static void main (String[] args)
	{
		int n=2;
		int evens=0;

		System.out.print ("Enter a number >=2: ");
		int input = Keyboard.readInt();

		if (input < 2)
		{
			System.out.println ("\nError: A number cannot be less than 2");

			System.out.print ("Please re-enter a number: ");
			input = Keyboard.readInt();
		}


		while (n<=input)
		{
			evens = evens + n;
			n=n+2;
		}
		System.out.println ("\nTotal sum of even numbers: " +evens+"\n");
	}
}