Xor is a binary operation which deal with ones and zeroes.

• 1 xor 1 is 0
• 0 xor 0 is 0 too

but

• 1 xor 0 is 1
• 0 xor 1 is 1

So we say that xor gives 1 when the arguments are different.

You will read two arguments (1 or 0 each) separated by space, print their xor result.

Input

a b (separated by space)

0 <= a, b <= 1

Output

The result of a xor b.

(Don't print end of line character, just print the result.)

Example

Input:
1 1

Output:
0