private void moverNaves() {
        int nNaves = juego.getnNaves();
        List<Nave> nav = naves;
        List<Nave> list;
        try{
        list = (nNaves == 2) ? nav : nav.subList(0, 1);
        
        if(moverListSolido(list)<=0)
            gameOver(); 
        }catch(java.lang.IndexOutOfBoundsException e){
            e.printStackTrace();
        }
    }