计算2月份有几天的代码

#include<stdio.h>
int main()
{
unsigned year,month,day=28;
printf(“请按照XXXX年XX月,的格式输入年份和月份\n”);
scanf("%d%d",&year,&month);
day+=year%4000||year%40&&year%100;
month==2&&printf("%d年2月有%d天\n",year,day);
return 0;
}