import re

def prime_factors(n):
    """
    Returns a list of prime factors for n.

    :param n: number for which prime factors should be returned
    """
    factors = []
    rest = n
    divisor = 2
    while rest % divisor == 0:
        factors.append(divisor)
        rest //= divisor
    divisor = 3
    while divisor * divisor <= rest:
        while rest % divisor == 0:
            factors.append(divisor)
            rest //= divisor
        divisor += 2
    if rest != 1:
        factors.append(rest)
    return factors

def lcm(numbers: list[int]) -> int:
    fs = []
    for n in numbers:
        fs += prime_factors(n)
    s = 1
    fs = list(set(fs))
    for f in fs:
        s *= f
    return s

def str_to_single_int(line: str) -> int:
    line = line.replace(" ", "")
    r = re.compile(r"-?\d+")
    for m in r.findall(line):
        return int(m)
    raise Exception("No single digit sequence in '{line}'")

def str_to_int_list(line: str) -> list[int]:
    r = re.compile(r"-?\d+")
    return list(map(int, r.findall(line)))

def str_to_lines_no_empty(text: str) -> list[str]:
    return list(filter(lambda l: l.strip() != "", text.splitlines()))

def str_to_lines(text: str) -> list[str]:
    return list(text.splitlines())