#include<stdio.h>
main()
{
int a,b;
printf("请分别输入一个年份和月份:");
scanf("%d%d",&a,&b);
switch(b)
{
case 1:
case 3:
case 5:
case 7:
case 8:
case 10
case 12:
    printf("%d年的第%d月有31天",a,b);
    break;
case 4:
case 6:
case 9:
case 11:
    printf("%d年的第%d月有30天",a,b);
    break;
default:
    if(a%4==0&&a%100!==0||a%400==0)
        printf("%d年的第%d月有29天",a,b);
    else
        printf("%d年的第%d月有28天",a,b);
    break;
}
}