[백준] 1316번 그룹 단어 체커 python

n = int(input())
answer = 0
for i in range(n):
    word = input()
    flag = 0
    for j in range(len(word)-1):
        if word[j] != word[j+1]:
            nword = word[j+1:]
            if word[j] in nword:
                flag = 1
    if flag ==0:
        answer +=1
print(answer)