from typing import List


def from_bits(bits: List[int]) -> int:
    """
    Convert a set of bits, least significant bit first to an integer.

    :param bits: List of bits, least significant bit first.
    :return: Integer representation of the bits.
    """
    base = 1
    integer = 0
    for bit in bits:
        if bit == 1:
            integer += base
        base *= 2
    return integer