#!/usr/bin/env python

count1=[0,0,0,0,0,0,0,0,0,0,0,0]
count=0
code_len=12

with open("input01.txt", "r") as f:
    for line in f:
        count += 1
        for pos in range(code_len):
            if line[pos] == '1':
                count1[pos] += 1

gama=''
epsilon=''

for pos in range(code_len):
   if (count1[pos] > count/2):
       gama=gama+'1'
       epsilon=epsilon+'0'
   else:
       gama=gama+'0'
       epsilon=epsilon+'1'

print(int(gama,2) * int(epsilon,2))