write a go solution for Description:
There is an empty matrix M of size nxm.

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=operatornameMEX(M_1,i,M_2,i,ldots,M_n,i)^ddagger. Since Daniel likes diversity, the beauty of M is s=operatornameMEX(v_1,v_2,*s,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 operatornameMEX of an array is the smallest non-negative integer that does not belong to the array. For example, operatornameMEX(2,2,1)=0 because 0 does not belong to the array, and operatornameMEX(0,3,1,2)=4 because 0, 1, 2 and 3 appear in the array, but 4 does not.

Input Format:
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*10^5) — the size of the matrix.

It is guaranteed that the sum of n*m over all test cases does not exceed 2*10^5.

Output Format:
For each test case, in the first line output a single integer — the maximum beauty of M.

Then output the matrix M of size nxm — the matrix you find.

If there are multiple solutions, you may output any of them.

Note:
In the first test case:

- v_1=operatornameMEX(1,0,1,0)=2;
- v_2=operatornameMEX(0,2,0,2)=1;
- v_3=operatornameMEX(2,1,2,1)=0.

Therefore, s=operatornameMEX(2,1,0)=3.

It can be shown that 3 is the maximum possible beauty of M.

In the second test case, any permutation will make s=2.

In the third test case:

- v_1=operatornameMEX(3,5,1,4,4,2)=0;
- v_2=operatornameMEX(0,2,3,1,2,4)=5;
- v_3=operatornameMEX(1,1,2,3,5,0)=4;
- v_4=operatornameMEX(4,0,4,2,3,5)=1;
- v_5=operatornameMEX(2,4,5,5,0,1)=3;
- v_6=operatornameMEX(5,3,0,0,1,3)=2.

Therefore, s=operatornameMEX(0,5,4,1,3,2)=6.. Output only the code with no comments, explanation, or additional text.