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 Common Lisp (SBCL 1.1.14) (judge verdict: Runtime Error)

(defun gen (str1 str2 &optional s)
  (cond ((equal str1 "") s)
    (t (gen (subseq str1 1) (subseq str2 1)
       (concatenate 'string s (subseq str1 0 1)(subseq str2 0 1)))))
  )


(let* ((n (read))
       (s (read-line))
       (str1 (subseq s 0 n))
       (str2 (subseq s (+ n 1))))
      (format t "~A~%" (gen str1 str2)))