#include<bits/stdc++.h>
using namespace std;
int main(){
    int ans=0;
    vector<int> a={31,28,31,30,31,30,31,31,30,31,30,31};
    for(int i=0;i<12;++i){
        for(int j=1;j<=a[i];++j){
            int x=j%10,y=j/10;
            if(i+1==x+y){
                ++ans;
            }
        }
    }
    cout<<ans<<endl;
}