class Bitarray:
    def __init__(self, num_bits):
        self.word_size = 32
        self.word_mask = 2**self.word_size - 1
        num_words = num_bits // self.word_size
        if num_bits % self.word_size != 0:
            num_words += 1
        self.num_bits = num_bits
        self.num_words = num_words
        self.array = [0] * num_words

    def setall(self, target: bool):
        if target:
            self.array = [self.word_mask] * self.num_words
        else:
            self.array = [0] * self.num_words

    def set(self, bit, target: bool):
        assert(bit < self.num_bits)
        word_index = bit // self.word_size
        bit_index = bit % self.word_size
        value = self.array[word_index]
        if target:
            value = (value | (1 << bit_index))
        else:
            value = (value & (~(1 << bit_index)))
        self.array[word_index] = value

    def get(self, bit) -> bool:
        assert(bit < self.num_bits)
        word_index = bit // self.word_size
        bit_index = bit % self.word_size
        return bool(self.array[word_index] & (1 << bit_index))

    def __getitem__(self, bit: int) -> bool:
        return self.get(bit)

    def __setitem__(self, bit: int, value: bool):
        self.set(bit, value)