B"Note: The XOR-sum of set {s_1,s_2, ldots,s_m } is defined as s_1 oplus s_2 oplus ldots oplus s_m , where oplus denotes the bitwise XOR operation. After almost winning IOI, Victor bought himself an n x n grid containing integers in each cell. n is an even integer. The integer in the cell in the i -th row and j -th column is a_{i,j} . Sadly, Mihai stole the grid from Victor and told him he would return it with only one condition: Victor has to tell Mihai the XOR-sum of all the integers in the whole grid. Victor doesn't remember all the elements of the grid, but he remembers some information about it: For each cell, Victor remembers the XOR-sum of all its neighboring cells. Two cells are considered neighbors if they share an edge -- in other words, for some integers 1 <= i, j, k, l <= n , the cell in the i -th row and j -th column is a neighbor of the cell in the k -th row and l -th column if |i - k| = 1 and j = l , or if i = k and |j - l| = 1 . To get his grid back, Victor is asking you for your help. Can you use the information Victor remembers to find the XOR-sum of the whole grid? It can be proven that the answer is unique. The first line of the input contains a single integer t ( 1 <= t <= 100 ) -- the number of test cases. The description of test cases follows. The first line of each test case contains a single even integer n ( 2 <= q n <= q 1000 ) -- the size of the grid. Then follows n lines, each containing n integers. The j -th integer in the i -th of these lines represents the XOR-sum of the integers in all the neighbors of the cell in the i -th row and j -th column. It is guaranteed that the sum of n over all test cases doesn't exceed 1000 and in the original grid 0 <= q a_{i, j} <= q 2^{30} - 1 . Hack Format To hack a solution, use the following format: The first line shou"...