public static void main(String args[]) {
		int input[][] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 }, { -1, 0, -1 } };
		PhoneDialNumberOfCombinationOfSizeK pdn = new PhoneDialNumberOfCombinationOfSizeK();
		System.out.println(pdn.numberOfCombination(3, input));
	}
-1 in the input means don't use that position

@param k
@param input
@return
src/com/interview/dynamic/PhoneDialNumberOfCombinationOfSizeK.java