import java.util.*;
import java.io.*;

public class GettingDaysInMonth{
	public static void main(String[] args) throws IOException{
		int year = 1;
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		System.out.print("Enter year : ");
		try{
			year = Integer.parseInt(in.readLine());
			if (year < 1900 || year > 2100){
				System.out.println("Please enter year greater than 1900 and less than 2100.");
				System.exit(0);
			}
		}
		catch(NumberFormatException ne){
			System.out.print(ne.getMessage() + " is not a valid entry.");
			System.out.println("Please enter a four digit number.");
			System.exit(0);
		}
		Calendar cal = new GregorianCalendar(year, Calendar.FEBRUARY, 1);
		int days = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
		System.out.print("Number of days : " + days);
	}
}