#include<bits/stdc++.h>
using namespace std;

const long long INF = 1LL << 60;
#define MOD 1000000007;

typedef long long ll;

#define writeln(n) cout<<n<<endl;

typedef pair<float, float> P;

typedef pair<string, int> Psi;

int days[] ={0,31,28,31,30,31,30,31,31,30,31,30,31};
int main() {


	int cnt=0;
	for(int i=1; i<=12; i++){

		int y =i;

		for(int j=1; j<=days[i]; j++){
			if(y == j/10+j%10){
				cnt++;
			/*	cout<<i<<"月"<<j<<"日"<<endl;*/
			}
		}
	}

	writeln(cnt);
}