public class No188{
    public static void main(String[] args){
        int lastday = -1;
        int count = 0;
        for(int month=1; month<=12; month++){
            switch(month){
                case 1:
                case 3:
                case 5:
                case 7:
                case 8:
                case 10:
                case 12:
                    lastday = 31;
                case 2:
                    lastday = 28;
                case 4:
                case 6:
                case 9:
                case 11:
                    lastday = 30;
            }
            for(int day=1; day <= lastday; day++){
                if(month == day/10+day%10){
                    count += 1;
                }
            }
        }
        System.out.println(count);
    }
}