public class MyDate {
    private int year;
    private int month;
    private int day;

    private int[] monthDurations = new int[] {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

    public String toString() {
        return String.format("%04d-%02d-%02d", year, month, day);
    }

    public MyDate tomorrow() {
        MyDate newDate = new MyDate(this.year, this.month, this.day+1);

        if (newDate.day > monthDurations[newDate.month-1]) {
            newDate.day = 1;
            newDate.month += 1;
        }

        if (newDate.month > 12) {
            newDate.month = 1;
            newDate.year += 1;
        }

        return newDate;
    }

    public MyDate(int y, int m, int d) {
        this.year = y;
        this.month = m;
        this.day = d;
    }
}