class No_188{
	public static void main(String[] args){

		int hd = 0;
		int dl ;

		for(int m = 1;m <= 12;m++){

		if(m == 4||m == 6||m == 9||m == 11){
		dl = 30;
		}else if(m == 2){
		dl = 28;
		}else{
		dl = 31;
		}

		for(int d = 1;d <= dl;d++){
		if(m == d / 10 + (d - d / 10 * 10)){
		hd++;
		}
		}
		}

		System.out.println(hd);
	}
}