#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m;
	cin>>n>>m;
	if(n%4==0&&n%100!=0||n%400==0){
		cout<<29;
	}else{
		cout<<28;
	}
} 
/**************************************************************
	Problem: 1825
	User: linzihang
	Language: C++
	Result: Wrong Answer
****************************************************************/