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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args:Array<String>) {
    val a = readLine()!!
    val b = readLine()!!
    val ls:List<String> = listOf(a,b)
    val l:MutableList<String> = mutableListOf("1","2","3")
    for (x in ls) {
        l.remove(x)
    }
    println(l[0])
}