import java.util.*;
public class No188 {
    public static void main(String[] arg){
       int hDay = 0, yDay,  X, Y;
       Calendar cal = Calendar.getInstance();
       cal.set(2015,11,31);
       yDay = cal.get(Calendar.DAY_OF_YEAR);
       cal.set(2015, 0, 1);
       for (int i=0;i<yDay-1;i++){
           X = cal.get(Calendar.MONTH);
           Y = cal.get(Calendar.DATE);
           if(X+1 == (Y/10 + Y%10)){
              ++hDay;
           }
           cal.add(Calendar.DATE, 1);
        }
        System.out.println(hDay);
    }
}