백준-1316

num = int(input())
all_words = [list(input()) for n in range(num)]
result = 0


for n in range(num):
  used = []
  words = all_words[n]
  check = True
  for i in range(len(words)):
    if i > 0 and words[i] in used and words[i] != words[i-1]:
      check = False
      break
    used.append(words[i])
  if check == True:
    result += 1
    

print(result)