B'You are given two integers l <= 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 <= t <= 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 <= l <= r <= 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. In the first test case, 11 <= 6 + 9 <= 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 <= a + b <= 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 . '...