c++

#include <bits/stdc++.h>
using namespace std;
int main(){
int n;
cin >> n;
if (n1 || n3 || n5 || n7 || n8 || n10 || n12){
cout << 31;
}else if(n2){
cout << 28;
}else{
cout << 30;
}
return 0;
}