Codeforces Round 895 (Div. 3) |
---|
Finished |
You are given two integers $$$l \le r$$$. You need to find positive integers $$$a$$$ and $$$b$$$ such that the following conditions are simultaneously satisfied:
or report that they do not exist.
$$$\gcd(a, b)$$$ denotes the greatest common divisor of numbers $$$a$$$ and $$$b$$$. For example, $$$\gcd(6, 9) = 3$$$, $$$\gcd(8, 9) = 1$$$, $$$\gcd(4, 2) = 2$$$.
The first line of the input contains an integer $$$t$$$ ($$$1 \le t \le 500$$$) — the number of test cases.
Then the descriptions of the test cases follow.
The only line of the description of each test case contains $$$2$$$ integers $$$l, r$$$ ($$$1 \le l \le r \le 10^7$$$).
For each test case, output the integers $$$a, b$$$ that satisfy all the conditions on a separate line. If there is no answer, instead output a single number $$$-1$$$.
If there are multiple answers, you can output any of them.
1111 151 318 1941 43777 7778000000 100000002000 20231791791 17917911 42 39840769 9840769
6 9 -1 14 4 36 6 111 666 4000000 5000000 2009 7 -1 2 2 -1 6274 9834495
In the first test case, $$$11 \le 6 + 9 \le 15$$$, $$$\gcd(6, 9) = 3$$$, and all conditions are satisfied. Note that this is not the only possible answer, for example, $$$\{4, 10\}, \{5, 10\}, \{6, 6\}$$$ are also valid answers for this test case.
In the second test case, the only pairs $$$\{a, b\}$$$ that satisfy the condition $$$1 \le a + b \le 3$$$ are $$$\{1, 1\}, \{1, 2\}, \{2, 1\}$$$, but in each of these pairs $$$\gcd(a, b)$$$ equals $$$1$$$, so there is no answer.
In the third sample test, $$$\gcd(14, 4) = 2$$$.
Name |
---|