백준 [ALGORITHM] - 그룹 단어 체커 (1316)

def check_func(word):
    flag = True
    checked = set()
    save_chars = ''

    for char in word:
        if char in checked and char != save_chars:
            flag = False

        checked.add(char)
        save_chars = char

    return flag


n = int(input())
cnt = 0

for i in range(n):
    flag = check_func(input())
    if flag == True:
        cnt += 1

print(cnt)