A. Distancetime limit per test3 secondsmemory limit per test512 megabytesinputstandard inputoutputstandard outputLet's denote the Manhattan distance between two points p_1 (with coordinates (x_1, y_1)) and p_2 (with coordinates (x_2, y_2)) as d(p_1, p_2) = |x_1 - x_2| + |y_1 - y_2|. For example, the distance between two points with coordinates (1, 3) and (4, 2) is |1 - 4| + |3 - 2| = 4.You are given two points, A and B. The point A has coordinates (0, 0), the point B has coordinates (x, y).Your goal is to find a point C such that:  both coordinates of C are non-negative integers;  d(A, C) = \dfrac{d(A, B)}{2} (without any rounding);  d(B, C) = \dfrac{d(A, B)}{2} (without any rounding). Find any point C that meets these constraints, or report that no such point exists.InputThe first line contains one integer t (1 \le t \le 3000) — the number of test cases.Each test case consists of one line containing two integers x and y (0 \le x, y \le 50) — the coordinates of the point B.OutputFor each test case, print the answer on a separate line as follows:  if it is impossible to find a point C meeting the constraints, print "-1 -1" (without quotes);  otherwise, print two non-negative integers not exceeding 10^6 — the coordinates of point C meeting the constraints. If there are multiple answers, print any of them. It can be shown that if any such point exists, it's possible to find a point with coordinates not exceeding 10^6 that meets the constraints. ExampleInput
10
49 3
2 50
13 0
0 41
42 0
0 36
13 37
42 16
42 13
0 0
Output
23 3
1 25
-1 -1
-1 -1
21 0
0 18
13 12
25 4
-1 -1
0 0
NoteExplanations for some of the test cases from the example:  In the first test case, the point B has coordinates (49, 3). If the point C has coordinates (23, 3), then the distance from A to B is |49 - 0| + |3 - 0| = 52, the distance from A to C is |23 - 0| + |3 - 0| = 26, and the distance from B to C is |23 - 49| + |3 - 3| = 26.  In the second test case, the point B has coordinates (2, 50). If the point C has coordinates (1, 25), then the distance from A to B is |2 - 0| + |50 - 0| = 52, the distance from A to C is |1 - 0| + |25 - 0| = 26, and the distance from B to C is |1 - 2| + |25 - 50| = 26.  In the third and the fourth test cases, it can be shown that no point with integer coordinates meets the constraints.  In the fifth test case, the point B has coordinates (42, 0). If the point C has coordinates (21, 0), then the distance from A to B is |42 - 0| + |0 - 0| = 42, the distance from A to C is |21 - 0| + |0 - 0| = 21, and the distance from B to C is |21 - 42| + |0 - 0| = 21. 
10
49 3
2 50
13 0
0 41
42 0
0 36
13 37
42 16
42 13
0 0

23 3 1 25 -1 -1 -1 -1 21 0 0 18 13 12 25 4 -1 -1 0 0 
['brute force', 'constructive algorithms', '*800']