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 Python (3.4.3) (judge verdict: Runtime Error)

n = int(input())
a = list(map(int, input().split()))

i = 0
j = 0
bt = 0

while i < n:
  while j < n - i:
    if a[i+j] == i+1:
      bt += 1
      break
    if j + i == n-1:
      if i == 0:
        bt = -1
      j = n + 1
      i = n + 1
      
    j += 1
  i += 1
  
if bt != -1:
  bt = n - bt
  
print(bt)