If a is equal to the power of x minus the power of two times XY plus y, and B is equal to the power of x plus the power of two times XY plus y, then A-B is equal to

If a is equal to the power of x minus the power of two times XY plus y, and B is equal to the power of x plus the power of two times XY plus y, then A-B is equal to

-4xy