#!/usr/bin/env python3

def is_bit_set(integer, bit_index):
   return bool(integer & (1 << bit_index))

def get_mcv(_input):
    input_length = len(_input)
    popcounts = [0 for bit in range(len(_input[0].strip()))]
    #print(popcounts)
    for line in _input:
        popcounts = list(map(int.__add__, popcounts, [int(bit) for bit in line.strip()]))
    mcv = []
    for val in popcounts:
        if val >= (input_length/2):
            mcv.append(1)
        else:
            mcv.append(0)
    return mcv

def main():
    content = open('input', 'r').readlines()
    #mcv = get_mcv(content)
   # mask = (1 << len(popcounts)) - 1
   # gamma_rate = int(gamma_rate, 2)
   # epsilon_rate = gamma_rate ^ mask

   # print(f'gamma: {bin(gamma_rate)}')
   # print(f'epsil: {bin(epsilon_rate)}')
    #print(f'mcv: {mcv}')
    bit_length = len(content[0].strip())
    oxy_input = content
    while len(oxy_input) > 1:
        offset = 0
        while offset < bit_length:
            mcv = get_mcv(oxy_input)
            print(mcv)
            print(f'length {len(oxy_input)} offset {offset} mcv {mcv[offset]} ')
            oxy_input = [x for x in oxy_input if int(x[offset]) == mcv[offset]]
            if len(oxy_input) == 1:
                break
            offset += 1
    oxygen_value = int(oxy_input[0].strip(), 2)
    
    co_input = content
    while len(co_input) > 1:
        offset = 0
        while offset < bit_length:
            print(f'length {len(co_input)}  offset {offset} mcv {mcv[offset]} ')
            mcv = get_mcv(co_input)
            print(mcv)
            co_input = [x for x in co_input if int(x[offset]) != mcv[offset]]
            if len(co_input) == 1:
                break
            offset += 1
    co_value = int(co_input[0].strip(), 2)
    print(co_value * oxygen_value)




    

if __name__ == "__main__":
    main()