.

```cpp
#include<bits/stdc++.h>
using namespace std;
bool check(int year)
{
    if(year%4==0&&year%100!=0||year%400==0)return 1;
    else return 0;
}
int check1(int n,int m)
{
    if(m==1||m==3||m==5||m==7||m==8||m==10||m==12)return 31;
    else if(m==4||m==6||m==9||m==11)return 30;
         else if(m==2&&check(n))return 29;
              else return 28;
}
int main()
{
	int n,m;
    cin>>n>>m;
    cout<<check1(n,m);
	return 0;
}

请注意闰年