package main

import (
	"bufio"
	"fmt"
	"os"
)

//const entryBits = 12
//const entryBits = 5

func main() {
	zeroes := [entryBits]int{}
	ones := [entryBits]int{}

	s := bufio.NewScanner(os.Stdin)
	for s.Scan() {
		for i, v := range s.Bytes() {
			if v == '0' {
				zeroes[i]++
			} else {
				ones[i]++
			}
		}
	}

	gamma := 0

	for i := range zeroes {
		if ones[i] > zeroes[i] {
			gamma |= 1 << (entryBits - i - 1)
		}
	}


	epsilon := gamma ^ ((1 << entryBits) - 1)

	fmt.Println(gamma * epsilon)
}