total = 1
number = []

with open("input") as f:
    for line in f:
        number.append(line.strip())

number_oxy = list(number)
number_co2 = list(number)


i = 0
while len(number_oxy) > 1 and i < len(number_oxy[0]):
    number_1 = len(list(filter(lambda x: x[i] == '1', number_oxy)))
    total = len(number_oxy)
    if number_1 >= total - number_1 :
        keep = '1'
    else:
        keep = '0'
    number_oxy = [ number for number in number_oxy if number[i] == keep]
    i += 1

i = 0
while len(number_co2) > 1 and i < len(number_co2[0]):
    number_0 = len(list(filter(lambda x: x[i] == '0', number_co2)))
    total = len(number_co2)
    if number_0 > total - number_0 :
        keep = '1'
    else:
        keep = '0'
    number_co2 = [ number for number in number_co2 if number[i] == keep]
    i += 1

oxy_rate = int("".join(number_oxy[0]), 2)
CO2_rate = int("".join(number_co2[0]), 2)

print(oxy_rate * CO2_rate)