#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(),x.end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
template<class T> inline bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T&a,T b){if(a>b){a=b;return 1;}return 0;}
using ll = long long;

int ans;
int day[]={31,28,31,30,31,30,31,31,30,31,30,31};

int main(){
    rep(i,12)rep(j,day[i]){
        if(i+1==j/10+j%10) ans++;
    }
    cout << ans << endl;
}