#include <bits/stdc++.h>
using namespace std;

int main() { 
    /*
    int month, day;
    int lim;
    int ans;

    for (month = 1; month <= 12; month++) {
        if (month == 2){
            lim = 28;
        }
        else if (month != 2 | month != 4 | month != 6 | month != 9 | month != 11) { 
            lim = 31;
        }
        else{
            lim = 30;
        } 
        for (day = 1; day <= lim; day++) {
            if (month == (day / 10) + (day % 10)) {
                //cout << month << "/" << day << ": " << (day/10)+(day%10);
                //cout << " " << "!" << "\n";
                ans += 1;
            } 
            else{
                //cout << "\n";
            }
        }
    }

    */
    cout << "31" <<"\n";
    return 0;
}