#include <bits/stdc++.h>
using namespace std;
int main(){
int month[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
int sum = 0;
for(int i = 0;i < 12;i++){
for(int j = 1;j <= month[i];j++){
if(i + 1 == j / 10 + j % 10)sum++;
}
}
cout << sum << endl;
return 0;
}