#include<bits/stdc++.h>
using namespace std;
int main(){
    int a,b;
    scanf("%d\\%d",&a,&b);
    
    if(((a%400==0)||(a%4==0&&a%100!=0))&&(b==2))cout<<29;
    else if (((a%400!=0)&&(a%4!=0||a%100==0))&&(b==2))cout<<28;
    else if(b==4||b==6||b==9||b==11)cout<<30;
    else cout<<31;
    return 0;
    
}