days = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
res = 0
for x in range(1, 13):
  for y in range(1, days[x] + 1):
    if x == y // 10 + y % 10:
      res += 1

print(res)