def lz78_compress(data: bytes) -> list:
    dictionary = {b'': 0}
    next_index = 1
    result = []
    current_phrase = b''
    for char in data:
        new_phrase = current_phrase + char.to_bytes(1, 'big')
        if new_phrase in dictionary:
            current_phrase = new_phrase
        else:
            result.append((dictionary[current_phrase], char))
            dictionary[new_phrase] = next_index
            next_index += 1
            current_phrase = b''
    if current_phrase:
        result.append((dictionary[current_phrase], 0))
    return result

def compress(input_file, output_file):
    with open(input_file, 'rb') as f:
        original_data = f.read()
    compressed_data = lz78_compress(original_data)
    len_compressed_data = len(compressed_data)
    with open(output_file, 'wb') as out:
        out.write(len_compressed_data.to_bytes(2, 'big'))
        for index, char in compressed_data:
            out.write(index.to_bytes(2, 'big'))
            out.write(char.to_bytes(1, 'big'))

if __name__ == '__main__':
    compress('Q7B.bmp', 'Q7B.bin')