C

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define pb     push_back


int main()
{
    _test
    {
        int n, m;
        cin>>n>>m;

        int maxMexPoss = min(n, m-1);

        vector<vector<int>> a(n, vector<int> (m));

        for(int i=0; i<n; i++)
        {
            for(int j=0; j<m; j++)
                a[i][j] = j;
        }

        for(int i=1; i<maxMexPoss; i++)
        {
            for(int j=0; j<=maxMexPoss; j++)
                a[i][j] = a[i-1][(j+1)%(maxMexPoss+1)];
        }

        for(int i=maxMexPoss; i<n; i++)
            a[i] = a[0];

        cout<<maxMexPoss+1 - (m==1)<<"\n";
        for(auto e: a)
        {
            for(auto f: e)
                cout<<f<<" ";
            cout<<"\n";
        }
    }
}