#include <cstdio>
#include <cassert>
#include <algorithm>
using namespace std;

int Tn, n, m, i, j, an, ax[100], ay[100], k, x, y, kx[100], py[100], it, u[100][100];
char a[100][100], b[100][100];
bool fl, fr, fail, fb, fk;

int main (int argc, char * const argv[]) {
	scanf("%d", &Tn);
	assert(1 <= Tn && Tn <= 10);
	while (Tn--) {
		an = 0;
		scanf("%d %d", &n, &m);
		assert(1 <= n && n <= 50);
		assert(1 <= m && m <= 50);
		for(i = 1; i <= n; i++) 
			for(j = 1; j <= m; j++) {
				a[i][j] = getchar();
				while (a[i][j] != '.' && a[i][j] != 'E' && a[i][j] != 'L') a[i][j] = getchar();
				if (a[i][j] == 'L') {
					++an;
					ax[an] = i;
					ay[an] = j;
				}
			}
		assert(1 <= an && an <= 16);
		for(i = 0; i < (1 << an); i++) {
			++it; fb = false;
			for(j = 1; j <= an; j++) if (i & (1 << (j - 1))) {
				x = ax[j];
				y = ay[j];
				fk = false;
				while (x > 0) {
					if (u[x][y] == it) {
						fb = true;
						break;
					}
					u[x][y] = it;
					fk |= (a[x][y] == 'E');
					--x;
				}
				fb |= !fk;
				if (fb) break;
			}
			if (fb) continue;
			for(j = 1; j <= n; j++) kx[j] = 0;
			for(j = 1; j <= an; j++) if ((i & (1 << (j - 1))) == 0) {
				++kx[ax[j]];
				py[ax[j]] = ay[j];
			}
			fail = false;
			for(j = 1; j <= n; j++) if (kx[j] < 2) {
				fl = fr = false;
				for(k = 1; k <= m; k++) 
					if (a[j][k] == 'E' && u[j][k] != it && py[j] > k) fl = true; else 
						if (a[j][k] == 'E' && u[j][k] != it) {
							fr = true;
							break;
						}
				if (kx[j] == 0 && (fl || fr)) {
					fail = true;
					break;
				}
				if (fl && fr) {
					fail = true;
					break;
				}
			}
			if (!fail) {
				puts("Possible");
				break;
			}
		}
		if (i == (1 << an)) puts("Impossible");
	}
    return 0;
}