2.2
# include <stdio.h>
int main()
{
int year,month=2,days;
printf("input the year:");
scanf("%d",&year);
if(((year%100!=0)&&(year%4==0))||((year%100==0)&&(year%400==0)))
{days=29; printf("year:%d,month:2,days:29",year);}
else{ days=28; printf("year:%d,month:2,days:28",year); };
return 0;
}