#include <iostream>
using namespace std;

int main(){
	int month = 0, day = 0, max = 0, total = 0;
	for(month = 1; month <= 12; month++){
		switch(month){
		case 1: case 3: case 5: case 7: case 8: case 10: case 12:
			max = 31;
			break;
		case 2:
			max = 28;
			break;
		case 4:	case 6:	case 9:	case 11:
			max = 30;
			break;
		default:
			break;
		}
		for(day = 1; day <= max; day++){
			if(month == (day%10 + day/10)) total++;
		}
	}
	cout << total << endl;
	return 0;
}