b=0
for i in range(1,13):
 for j in range(1,32):

  if j>10:
   a=j//10+(j-(j//10*10)) 

  else:
   a=j

  if i==a:
   b+=1

  if i in {1,3,5,7,8,10,12} and j==31:
   break

  if i in {4,6,9,11} and j==30:
   break
  
  if i == 2 and j==28:
   break

print(b)