#include <stdio.h>

int main() {
	int m, d, d_max[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };
	int hd = 0;

	for (m = 1; m <= 12; m++) {
		for (d = 1; d <= d_max[m - 1]; d++) {
			if (m == (d / 10) + (d - (d / 10) * 10)) hd++;
		}
	}

	printf("%d\n", hd);

	return 0;
}