Bitwise Equations

You are given two positive integers x and k. Find 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.

Input

Each line is a separate test case which contains two integers x and k (1 ≤ x, k ≤ 2*10^9).

Output

For each test case print in a separate line the k-th smallest positive integer y for which the given above equation holds.

Examples