Problem:
Score: 100 points

Problem Statement

Takahashi is solving quizzes. He has easily solved all but the last one.

The last quiz has three choices: 1, 2, and 3.

With his supernatural power, Takahashi has found out that the choices A and B are both wrong.

Print the correct choice for this problem.

Constraints

Each of the numbers A and B is 1, 2, or 3.

A and B are different.

Input

Input is given from Standard Input in the following format:

A
B

Output

Print the correct choice.

Sample Input 1

3
1

Sample Output 1

2

When we know 3 and 1 are both wrong, the correct choice is 2.

Sample Input 2

1
2

Sample Output 2

3

Solution in Go (1.6) (judge verdict: Accepted)

package main

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

func main() {

	answer := "123"
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for i := 0; i < 2; i++ {
		sc.Scan()
		s := sc.Text()
		answer = strings.Replace(answer, s, "", 1)
	}

	fmt.Println(answer)
}