public class zy9 { public static void main(String[] args) { Scanner scanner=new Scanner(System.in); System.out.println("请输入年份"); int a= Integer.parseInt(scanner.next()); System.out.println("请输入月份"); int b= Integer.parseInt(scanner.next()); if(b==1||b==3||b==5||b==7||b==8||b==10||b==12){ System.out.println("这个月有31天"); }else if(b==4||b==6||b==9||b==11){ System.out.println("这个月有30天"); }else if(b==2){ if (a%4==0){ System.out.println("这个月有28天"); }else { System.out.println("这个月有29天"); } } } }