def ex_4_1():
    with open("liczby.txt", "r") as f:
        counter = 0
        first = None

        for line in f:
            if line.strip()[0] == line.strip()[-1]:
                if first is None:
                    first = line.strip()
                counter += 1

    return counter, first


def ex_4_2():
    def prime_factors(n):
        factors = []
        d = 2
        while n > 1:
            while n % d == 0:
                factors.append(d)
                n //= d
            d = d + 1
        return factors

    with open("liczby.txt", "r") as f:
        content = [int(line.strip()) for line in f]
        numbers = {}
        for number in content:
            numbers[number] = prime_factors(number)
        x = sorted([(len(v), k) for k, v in numbers.items()], reverse=True)
        _max = x[0][0]
        for i in x:
            if i[0] == _max:
                print(i)
        x = sorted(
            [(len(v), k) for k, v in numbers.items() if v == list(set(v))], reverse=True
        )
        _max = x[0][0]
        for i in x:
            if i[0] == _max:
                print(i)