import numpy as np
import pdb
def open_files(filenames: str) -> list:
    files = []
    for f in filenames:
        files.append(open(f, "r"))
    return files

# on lit un bit par fichier sur les 7
filenames = ["channel_"+ str(i) for i in range(1,9)]
files = open_files(filenames)

total_bits = []
current_row_bits = []
eof = 0
while not eof:
    for f in files[:-1]:
        bit = f.read(1)
        current_row_bits += bit
    parity_bit = files[-1].read(1)
    
    if len(current_row_bits) != 7:
        eof = 1
        break
    
    if current_row_bits.count('1') % 2 != int(parity_bit):
        current_row_bits[3] = str((int(current_row_bits[3])+1)%2)
    total_bits.extend(current_row_bits)
    current_row_bits = []

print("".join(total_bits))