PROBLEM STATEMENT

You are given two positive integers x and k. Return the k-th smallest positive integer y (where k 
is 1-based) for which the following equation holds:
x + y = x | y
where '|' denotes the bitwise OR operator.



DEFINITION
Class:BitwiseEquations
Method:kthPlusOrSolution
Parameters:int, int
Returns:long long
Method signature:long long kthPlusOrSolution(int x, int k)


CONSTRAINTS
-x will be between 1 and 2,000,000,000, inclusive.
-k will be between 1 and 2,000,000,000, inclusive.


EXAMPLES

0)
5
1

Returns: 2

The first positive integer for which the equation holds is 2.
You can check that 5+2=7 as well as 5|2=7. Both plus and bitwise OR look like the following:

 101
+ 10
 ---
 111



1)
5
5

Returns: 18

The fifth number for which the equation 5 + y = 5 | y holds is 18. The first four solutions are 
2,8,10,16.
The binary sum for 18 looks like the following:

   101
+10010
 -----
 10111


2)
10
3

Returns: 5

The third solution is 5. The first two solutions are 1 and 4.


3)
1
1000000000

Returns: 2000000000



 This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2010, TopCoder, Inc. All rights reserved.