import numpy as np
import calendar

if __name__ == "__main__":
	count = 0

	for i in range(1, 13): #1~12月
		days = calendar.monthrange(2015, i)[1] #月ごとの日数
		for j in range(1, days+1):
			if i == (j // 10 + j % 10):
				count += 1
	print(count)