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

int solver(int month, int day){
    int hd=0;
    for(int i=1;i<day+1;i++){
        if(i%10+(i/10)==month) {
            hd++;
        }
    }
    return hd;
}

int main(){
    int ans=0;

    ans+=solver(1,31);
    ans+=solver(2,28);
    ans+=solver(3,31);
    ans+=solver(4,30);
    ans+=solver(5,31);
    ans+=solver(6,30);
    ans+=solver(7,31);
    ans+=solver(8,31);
    ans+=solver(9,30);
    ans+=solver(10,31);
    ans+=solver(11,30);
    ans+=solver(12,31);

    cout << ans << endl;

    return 0;
}