public static void main(String[] args){
        String s = "dasdrgerhrthefgwegrtjtyjsfgvs";
        Set<Character> xx = new HashSet<>();

        for(int x = 0; x < s.toCharArray().length; x++){
            xx.add(s.toCharArray()[x]);
        }

        System.out.println("Size unique char is: " + xx.size());
    }