#include <bits/stdc++.h>

using namespace std;

int main()
{
    int d[]{31,28,31,30,31,30,31,31,30,31,30,31};
    int s{9};
    
    for(int i=1;i<=12;++i)
    {
        for (int j=10;j<=d[i-1];++j)
        {
            if (j/10+(j%10)==i)
                ++s;
        }
    }
    
    cout << s << "\n";
    
	return 0;
}