include "pch.h"

include

using namespace std;

int main() {

int year, mon;
int mday[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31};

while (cin>>year>>mon)
{
	if (mon>12|| mon<1) {
	
		cout << "error";
		continue;
	}
	//先判断是不是闰年
	bool isLeap = year % 400 == 0 || (year % 100!=0 && year % 4 == 0);

	if (isLeap) {
		
		//是闰年
		mday[2] = 29;
	
	}
	else
	{
		mday[2] = 28;
	}

	cout << mday[mon];


	
}

}