days_in_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
ans = 0
for i in range(12):
 month = i + 1
 max_day = days_in_month[i]
 for j in range(1,max_day + 1):
  if month == (j // 10) + (j % 10) :
   ans = ans + 1
  else:
   pass
print(ans)