from typing import Counter


def count_letters(input_):
    """
    Given an input_ like "abcdef" return a tuple with the result of the following rules
    a letter appears exactly 2 times
    a letter appears exactly 3 times
    """
    counter = Counter(input_)
    two_times = 0
    three_times = 0
    for quantity in counter.values():
        if quantity == 2:
            two_times += 1
        elif quantity == 3:
            three_times += 1
    return two_times > 0, three_times > 0