判断月份天数

import java.util.Scanner;


public class Month {
    public static void main(String [] args){
    Scanner input = new Scanner(System.in);
    while(input.hasNext()){
    int days;
    int month = input.nextInt();
    switch(month){
    case 2:days = 28;
         break;
    case 4:
    case 6:
    case 9:
    case 11:days = 30;
       break;
       default:days =31;
    }
    System.out.println(days);
    }
    }
}