#include<iostream>
#include<vector>
#include<algorithm>
#include<cstdio>
using namespace std;
int main(){
    int days[] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
    int ans = 0;
    for(int i=1;i<=12;i++){
        for(int j=1;j<=days[i];j++){
            if(i == j%10+(j/10))  ans++;
        }
    }
    cout << ans << endl;
    return 0;
}