Plus and xor

Bitwise exclusive OR (or bitwise addition modulo two) is a binary operation which is equivalent to applying logical exclusive OR to every pair of bits located on the same positions in binary notation of operands. In other words, a binary digit of the result is equal to 1 if and only if bits on the respective positions in the operands are different.

For example, if X = 109₁₀ = 1101101₂, Y = 41₁₀ = 101001₂, then:

Write a program, which takes two non-negative integers A and B as an input and finds two non-negative integers X and Y, which satisfy the following conditions:

• A = X + Y
• B  =  X xor Y, where xor is bitwise exclusive or.
• X is the smallest number among all numbers for which the first two conditions are true.