#include <iostream>
#include <algorithm>
#include <cmath>
#include <limits>
#include <iomanip>
#include <vector>
#include <cstring>
#include <queue>
#include <map>
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
using namespace std;
//typedef long long ll;
//typedef long double ld;
//typedef unsigned long long ull;
//typedef unsigned long double uld;
typedef pair<int,int> P;
const int dx[4] = {0,1,0,-1};
const int dy[4] = {1,0,-1,0};
template<class T> inline bool chmax(T &a,T& b){if(a < b){a = b; return true;} else return false;}
template<class T> inline bool chmin(T &a,T& b){if(a > b){a = b; return true;} else return false;}
//struct area

//function area

//main area
int main(){
    int count = 0;
    vector<int> month(12, 31);
    month[2] -= 3;
    month[4]--,  month[6]--, month[9]--, month[11]--;
    rep1(i, 12){
        rep1(j, month[i]){
            int k;
            if(j < 10) k = j;
            else k = j/10 + j%10;
            if(i == k) count++;
        }
    }
    cout << count << endl;
}
/*



*/