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:

X xor Y = 68₁₀ = 1000100₂.

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.

Input

The first line contains integer number A and the second line contains integer number B (0 ≤ A, B ≤ 2⁶⁴ - 1).

Output

The only output line should contain two integer non-negative numbers X and Y. Print the only number -1 if there is no answer.

Plus and xor

Examples