B'There is an empty matrix M of size n x m . Zhongkao examination is over, and Daniel would like to do some puzzle games. He is going to fill in the matrix M using permutations of length m . That is, each row of M must be a permutation of length m^ dagger . Define the value of the i -th column in M as v_i= operatorname{MEX}(M_{1,i},M_{2,i}, ldots,M_{n,i})^ ddagger . Since Daniel likes diversity, the beauty of M is s= operatorname{MEX}(v_1,v_2, cdots,v_m) . You have to help Daniel fill in the matrix M and maximize its beauty. ^ dagger A permutation of length m is an array consisting of m distinct integers from 0 to m-1 in arbitrary order. For example, [1,2,0,4,3] is a permutation, but [0,1,1] is not a permutation ( 1 appears twice in the array), and [0,1,3] is also not a permutation ( m-1=2 but there is 3 in the array). ^ ddagger The operatorname{MEX} of an array is the smallest non-negative integer that does not belong to the array. For example, operatorname{MEX}(2,2,1)=0 because 0 does not belong to the array, and operatorname{MEX}(0,3,1,2)=4 because 0 , 1 , 2 and 3 appear in the array, but 4 does not. The first line of input contains a single integer t ( 1 <= t <= 1000 ) -- the number of test cases. The description of test cases follows. The only line of each test case contains two integers n and m ( 1 <= n,m <= 2 cdot 10^5 ) -- the size of the matrix. It is guaranteed that the sum of n cdot m over all test cases does not exceed 2 cdot 10^5 . For each test case, in the first line output a single integer -- the maximum beauty of M . Then output the matrix M of size n x m -- the matrix you find. If there are multiple solutions, you may output any of them. In the first test case: Therefore, s= operatorna'...