#include <bits/stdc++.h>

[[nodiscard]] static inline constexpr uint_fast32_t solve() noexcept
{
	uint_fast32_t ans = 0;
	for (uint_fast32_t X = 1; X <= 12; ++X)
	{
		const auto count_in_month = [&](const uint_fast32_t final_day) constexpr noexcept -> void
			{
				for (uint_fast32_t Y = 1; Y <= final_day; ++Y)
					if (X == Y / 10 + Y % 10)
						++ans;
			};
		
		if (X == 2)
			count_in_month(28);
		else if ((X <= 7) ^ (X & 1))
			count_in_month(30);
		else
			count_in_month(31);
	}

	return ans;
}


int main()
{
	std::cin.tie(nullptr);
	std::ios::sync_with_stdio(false);

	std::cout << solve() << '\n';
	return 0;
}