Problem1558--Plus and xor

1558: Plus and xor

Time Limit: 2 Sec  Memory Limit: 256 MB
Submit: 0  Solved: 0
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Description

time limit per test
0.5 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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.

Examples
Input
142
76
Output
33 109

Source/Category

 
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