题解

#include<bits/stdc++.h>
#define ll long long                                                                                                                                                                                                //防伪标识
#define MAXN 1005
#define maxn 10005
#define MAXM 10000
#define maxm 1000005
using namespace std;
int y,m;
int main(){
	cin>>y>>m;
	if(m == 1||m == 3||m == 5||m == 7||m == 8||m == 10||m == 12) cout<<31;
	else if(m == 2){
		if(y%400 == 0||(y%4 == 0&&y%100!=0)) cout<<29;
		else cout<<28;
	}
	else cout<<30;
	return 0;
}