#!/usr/bin/env python

import copy

code_len=12
input=[]

with open("input01.txt", "r") as f:
    for line in f:
        input.append(line)

input_oxygen = copy.copy(input)
input_co2 = copy.copy(input)

# oxygen
for pos in range(code_len):
    if len(input_oxygen) == 1:
        break
    tmp = [i for i in input_oxygen if i[pos] == '1']
    filter = '1' if (len(tmp) >= len(input_oxygen)/2) else '0'
    input_oxygen = [i for i in input_oxygen if i[pos] == filter]
    

# co2
for pos in range(code_len):
    if len(input_co2) == 1:
        break
    tmp = [i for i in input_co2 if i[pos] == '1']
    filter = '1' if (len(tmp) < len(input_co2)/2) else '0'
    input_co2 = [i for i in input_co2 if i[pos] == filter]
 

print(int(input_oxygen[0], 2) * int(input_co2[0],2))