public List<String> findSubstring(String s, List<String> allKUniversals) {
        List<String> foundSubstrings = new ArrayList<String>();
        for (String string : allKUniversals) {
            int length = s.length();
            if (string.substring(0, length).equals(s) && !string.equals(s)) {
                foundSubstrings.add(string);
            }
        }

        return foundSubstrings;
    }