B'You are given an array a of n positive integers. In one operation, you must pick some (i, j) such that 1 <= q i < j <= q |a| and append |a_i - a_j| to the end of the a (i.e. increase n by 1 and set a_n to |a_i - a_j| ). Your task is to minimize and print the minimum value of a after performing k operations. Each test contains multiple test cases. The first line contains an integer t ( 1 <= q t <= q 1000 ) -- the number of test cases. The description of the test cases follows. The first line of each test case contains two integers n and k ( 2 <= n <= 2 cdot 10^3 , 1 <= k <= 10^9 ) -- the length of the array and the number of operations you should perform. The second line of each test case contains n integers a_1, a_2, ldots, a_n ( 1 <= a_i <= 10^{18} ) -- the elements of the array a . It is guaranteed that the sum of n^2 over all test cases does not exceed 4 cdot 10^6 . For each test case, print a single integer -- the smallest possible value of the minimum of array a after performing k operations. In the first test case, after any k=2 operations, the minimum value of a will be 1 . In the second test case, an optimal strategy is to first pick i=1, j=2 and append |a_1 - a_2| = 3 to the end of a , creating a=[7, 4, 15, 12, 3] . Then, pick i=3, j=4 and append |a_3 - a_4| = 3 to the end of a , creating a=[7, 4, 15, 12, 3, 3] . In the final operation, pick i=5, j=6 and append |a_5 - a_6| = 0 to the end of a . Then the minimum value of a will be 0 . In the third test case, an optimal strategy is to first pick i=2, j=3 to append |a_2 - a_3| = 3 to the end of a . Any second operation will still not make the minimum value of a be less than 3 . '...