B"Ehab loves number theory, but for some reason he hates the number x . Given an array a , find the length of its longest subarray such that the sum of its elements isn't divisible by x , or determine that such subarray doesn't exist. An array a is a subarray of an array b if a can be obtained from b by deletion of several (possibly, zero or all) elements from the beginning and several (possibly, zero or all) elements from the end. The first line contains an integer t (1 <= t <= 5) -- the number of test cases you need to solve. The description of the test cases follows. The first line of each test case contains 2 integers n and x ( 1 <= n <= 10^5 , 1 <= x <= 10^4 ) -- the number of elements in the array a and the number that Ehab hates. The second line contains n space-separated integers a_1 , a_2 , ldots , a_{n} ( 0 <= a_i <= 10^4 ) -- the elements of the array a . For each testcase, print the length of the longest subarray whose sum isn't divisible by x . If there's no such subarray, print -1 . In the first test case, the subarray [2,3] has sum of elements 5 , which isn't divisible by 3 . In the second test case, the sum of elements of the whole array is 6 , which isn't divisible by 4 . In the third test case, all subarrays have an even sum, so the answer is -1 . "...