with open("input") as f:
    puzzle_input = [n.strip() for n in f.readlines()]

# puzzle_input = ["qjhvhtzxzqqjkmpb", "xxyxx", "uurcxstgmygtbstg", "ieodomkazucvgmuy"]

nice_words = 0


def has_duplicate_pair(word):
    for idx_a in range(len(word) - 3):
        for idx_b in range(idx_a + 2, len(word) - 1):
            pair_1 = word[idx_a] + word[idx_a + 1]
            pair_2 = word[idx_b] + word[idx_b + 1]

            if pair_1 == pair_2:
                return True
    return False


def has_repeated_letter_with_one_between(word):
    for idx, a in enumerate(word[:-2]):
        b = word[idx + 2]
        if a == b:
            return True
    return False


def is_nice_word(word):
    return has_duplicate_pair(word) and has_repeated_letter_with_one_between(word)


for word in puzzle_input:
    if is_nice_word(word):
        nice_words += 1

print(nice_words)