// Model solution for problem A
// Author: Grzegorz Herman

#include <cassert>
#include <cstdio>
#include <utility>
#include <vector>
using namespace std;

int nrows, ncols;
vector<vector<int>> data;
vector<pair<bool,int>> moves;

bool invalid(int r, int c)
{
    return data[r][c] != (ncols * r + c + 1);
}

void move(bool d, int i)
{
    moves.push_back(make_pair(d, i));
    if (d)
        for (int col = 0, loc = ncols-1; col < loc; ++col, --loc)
            swap(data[i][col], data[i][loc]);
    else
        for (int row = 0, wor = nrows-1; row < wor; ++row, --wor)
            swap(data[row][i], data[wor][i]);
}

int main()
{
    int ncases;
    assert(1 == scanf("%d", &ncases));
    while (ncases-- > 0)
    {
        // read dimensions, allocate data structures
        assert(2 == scanf("%d%d", &ncols, &nrows));
        vector<vector<int>>(nrows, vector<int>(ncols)).swap(data);
        vector<pair<bool,int>>().swap(moves);
        // read the input
        for (int row = 0; row < nrows; ++row)
            for (int col = 0; col < ncols; ++col)
                assert(1 == scanf("%d", &data[row][col]));
        // handle middle row
        if (nrows % 2 == 1)
            for (int col = 0, row = nrows/2; col < ncols; ++col)
                if (invalid(row, col))
                    move(true, row);
        // handle middle column
        if (ncols % 2 == 1)
            for (int row = 0, col = ncols/2; row < nrows; ++row)
                if (invalid(row, col))
                    move(false, col);
        // handle quads
        for (int row = 0, wor = nrows-1; row < wor; ++row, --wor)
            for (int col = 0, loc = ncols-1; col < loc; ++col, --loc)
            {
                if (invalid(row, col)) { move(true, wor); move(false, col); move(true, wor); move(false, col); }
                if (invalid(row, col)) { move(false, loc); move(true, row); move(false, loc); move(true, row); }
                if (invalid(row, col)) { move(false, col); move(true, row); move(false, col); move(true, row); }
                if (invalid(wor, loc)) { move(false, loc); move(true, wor); move(false, loc); move(true, wor); }
                if (invalid(wor, loc)) { move(false, loc); move(true, wor); move(false, loc); move(true, wor); }
                if (invalid(row, loc))
                    if (col) { move(true, row); move(false, col); move(true, row); }
                    else     { move(false, col); move(true, row); move(false, col); }
            }
        // verify a solution has been found
        bool possible = true;
        for (int row = 0; row < nrows; ++row)
            for (int col = 0; col < ncols; ++col)
                if (invalid(row, col))
                    possible = false;
        // print the answer
        if (possible)
        {
            printf("POSSIBLE %lu", moves.size());
            for (int i = 0; i < moves.size(); ++i)
                printf(moves[i].first ? " R%d" : " C%d", moves[i].second+1);
            printf("\n");
        }
        else
            printf("IMPOSSIBLE\n");
    }
    return 0;
}