public class LeapYear {
	public static void main(String[] args) {
		System.out.println("A.D. 1900: " + isLeapYear(1900));
		System.out.println("A.D. 2000: " + isLeapYear(2000));
		System.out.println("A.D. 2008: " + isLeapYear(2008));
		System.out.println("A.D. 2009: " + isLeapYear(2009));
		System.out.println("A.D. 2100: " + isLeapYear(2100));
	}

	public static boolean isLeapYear(int aYear) {
		return isDivisible(aYear, 4) ? (isDivisible(aYear, 100) ? (isDivisible(aYear, 400) ? true : false) : true) : false;
	}

	public static boolean isDivisible(int aLeft, int aRight) {
		while (aLeft >= aRight) {
			aLeft -= aRight;
		}
		return aLeft == 0;
	}
}