class Test{
    public static void main(String args[]){
        try{
            String num="0";
            double d=Double.parseDouble(num);
            if(d==0.0){
                System.out.println("valid");
            }else if(d>0&&(num.split("\\.")[1].length()==2)){
                System.out.println("valid");
            }else{
                System.out.println("invalid");
            }
        } catch (NumberFormatException e){
            System.out.println("not a valid number");
        }
    }    
}