B"You are given a binary matrix b (all elements of the matrix are 0 or 1 ) of n rows and n columns. You need to construct a n sets A_1, A_2, ldots, A_n , for which the following conditions are satisfied: Set X is a proper subset of set Y , if X is a nonempty subset of Y , and X neq Y . It's guaranteed that for all test cases in this problem, such n sets exist. Note that it doesn't mean that such n sets exist for all possible inputs. If there are multiple solutions, you can output any of them. Each test contains multiple test cases. The first line contains a single integer t ( 1 <= t <= 1000 ) -- the number of test cases. The description of test cases follows. The first line contains a single integer n ( 1 <= n <= 100 ). The following n lines contain a binary matrix b , the j -th character of i -th line denotes b_{i,j} . It is guaranteed that the sum of n over all test cases does not exceed 1000 . It's guaranteed that for all test cases in this problem, such n sets exist. For each test case, output n lines. For the i -th line, first output s_i (1 <= s_i <= n) -- the size of the set A_i . Then, output s_i distinct integers from 1 to n -- the elements of the set A_i . If there are multiple solutions, you can output any of them. It's guaranteed that for all test cases in this problem, such n sets exist. In the first test case, we have A_1 = {1, 2, 3 }, A_2 = {1, 3 }, A_3 = {2, 4 }, A_4 = {1, 2, 3, 4 } . Sets A_1, A_2, A_3 are proper subsets of A_4 , and also set A_2 is a proper subset of A_1 . No other set is a proper subset of any other set. In the second test case, we have A_1 = {1 }, A_2 = {1, 2 }, A_3 = {1, 2, 3 } . A_1 is a proper subset of A_2 and A_3 , and A_2 is a proper subset of A"...