public class App
{
    public static void main( String[] words ) {
        HashMap<String, Integer> map = new HashMap<>();
                String firstWord = null;

        for (String word : words) {
            if (!map.containsKey(word)) {
                map.put(word, 1);
            } else {
                map.put(word, map.get(word) + 1);

            }
        }
        System.out.println(Arrays.toString(words));

        for (Map.Entry<String, Integer> entry : map.entrySet()) {
            System.out.println(entry.getKey() + " : " + entry.getValue());
            if (entry.getValue() == 1) {
                firstWord = entry.getKey();
            }
        }
        System.out.println(firstWord);

    }

}