백준 1316 파이썬

n= int(input())

answer=0

for _ in range(n):

    cnt=0

    

    a = input()

    for i in range(len(a)-1):

        if a[i]!=a[i+1]:

            new=a[i+1:]

            if new.count(a[i])>0:

                cnt+=1

    if cnt==0:

        answer+=1

print(answer)