#include<iostream>
#include<algorithm>
#include<vector>
#include<cmath>
#include<string>
#include<numeric>
#include<algorithm>
using namespace std;
int main()
{
    int ans = 0;
    for(int j=1;j<13;j++)
     for(int i=1;i<32;i++){
if(i == 31 && j == 2 || j == 4 || j == 6 || j == 9 || j == 11)continue;
if(j == i / 10 + i % 10)ans++;
     }
     cout << ans << endl;
     return 0;
}