class Apriori {

	static <T> Set<Set<T>> kMinusOneSubsets(Set<T> c) {
		Set<Set<T>> kMinusOneSubsets = new HashSet<>();
		for (T i : c) {
			Set<T> subset = new HashSet<T>(c);
			subset.remove(i);
			kMinusOneSubsets.add(subset);
		}
		return kMinusOneSubsets;
	}

	private  Apriori();

}