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.

Examples

Input

3
1

Output

2

Input

1
2

Output

3

见题面

见题面