public int getCount() {
		if(count < 0) {
			count = 0;
			for(Word word : words) {
				if(word != null) {
					count++;
				}
			}
		}
		return count;
	}
public int getCount ( ) { if ( count < 0 ) { count = 0 ; for ( Word word : words ) { if ( word != null ) { count ++ ; } } } return count ; }
有多少个词，最多3个。