public static void main(String[] args) {
 
        String prenom;
        Scanner sc= new Scanner(System.in);		
        char reponse=' ';
        int note;
        do{        
            System.out.println("Veuillez rentrer votre prenom:");
            prenom=sc.next();
            System.out.println("Bonjour," +prenom+ "! Rentre ta moyenne:");
            note= sc.nextInt();
            switch (note){
                case (0):
                System.out.println( "insuffisant");
                break;
                case (10):
                System.out.println("juste juste");
                break;
                case (20):
                System.out.print("genial !");
                break;
            }
            if (note>0 && note<10){
                        System.out.println("Travail encore plus!");
            }
            else if (note>10 && note<20){
                System.out.println("tu atteint presque la perfection!");                 
            }
            do{
                System.out.println("Veux tu recommencer? (O/N)");
                reponse= sc.next().charAt(0);                
            }while(reponse !='O' && reponse != 'N');
        }while (reponse=='O');

    }