#include<stdio.h>

typedef unsigned int u_int;

int main() {
	
	int day = 0;
	int ans = 0;

	for (int month = 1; month <= 12; month++) {
		switch (month)
		{
		case 2:
			day = 28;
			break;
		case 4:
		case 6:
		case 9:
		case 11:
			day = 30;
			break;
		default:
			day = 31;
			break;
		}
		if (month < 10)
			ans++;
		for (int i = 10; i <= day; i++) {
			if (i % 10 + i / 10 == month)
				ans++;
		}
	}
	printf("%d", ans);
	
	// 終了コードは0
	return 0;
}