#include<iostream>
#include<cstdio>
#include<vector>
using namespace std;

int main() {
	int count = 0;
	int n[13] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	for (int i = 1; i < 13; i++)
	{
		for (int k = 1; k <= n[i]; k++)
		{
			int temp = (k / 10) + (k % 10);
			if (k == temp)
			{
				count++;
			}
		}
	}
	cout << count << endl;

	return 0;
}