有人能教教我怎么编写这个程序吗？

public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        int day,month;
        String season;

        System.out.println("Enter day and month(dd mm):");
        day = sc.nextInt();
        month = sc.nextInt();
        if (month == 1 || month == 2 || month==3) {
            season = "Winter";
        }else if (month == 4 || month == 5 || month==6){
            season = "Spring";
        }else if (month == 7 || month == 8 || month==9){
            season = "Summer";
        }else{
            season = "Autumn";
        }
        if(month%3==0 && day>=21){
            if(season.equals("Winter")) season = "Spring";
            else if(season.equals("Spring")) season = "Summer";
            else if(season.equals("Summer")) season = "Autumn";
            else season = "Winter";
        }
        System.out.println("The season is "+season+".");
    }