public class HappyDay{
    public static void main(String[] args){

        int happyday = 0;
        for(int m=1; m<=12; m++){
            for(int d=1; d<=30; d++){
                int d1 = d/10;
                int d0 = d%10;
                if(m == d1+d0){
                    happyday++;
                    // System.out.println(m + "/" + d);
                }
            }
        }
        System.out.println(happyday);
    }
}