#include <bits/stdc++.h>

const int MAXN = 1005;

using namespace std;

char Mp[MAXN][MAXN];
bool Vis[MAXN][MAXN];

struct Point {
	int x, y;
};

const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, 1, -1};

int N, M;

inline bool BFS () {
	std::queue <Point> Q;
	Q.push ({1, 1});
	
	Point Now;
	
	while (!Q.empty ()) {
		Now = Q.front (), Q.pop ();
		
		if (Vis[Now.x][Now.y]) continue ;
		if (Now.x == N && Now.y == M) return 1;
		
		Vis[Now.x][Now.y] = 1;
		
		for (int i = 0; i < 4; ++ i) {
			if (Now.x + dx[i] < 1 || Now.x + dx[i] > N || Now.y + dy[i] < 1 || Now.y + dy[i] > M) continue ;
			if (Mp[Now.x + dx[i]][Now.y + dy[i]] == 'W') Q.push ({Now.x + dx[i], Now.y + dy[i]});
		}
	}
	
	return 0;
}

inline void Solve () {
	memset (Vis, 0, sizeof Vis);
	
	cin >> N >> M;
	
	for (int i = 1; i <= N; ++ i)
		for (int j = 1; j <= M; ++ j)
			cin >> Mp[i][j];
	
	bool IsC = BFS ();
	
	if (!IsC) return cout << "J" << '\n', void ();
	
	int Cnt = 0, Now = (N + M - 1);
	
	for (int i = 1; i <= N; ++ i)
		for (int j = 1; j <= M; ++ j)
			if (Mp[i][j] == 'W') ++ Cnt;
	
	cerr << Cnt << ' ' << Now << '\n';
	
	if ((Cnt - Now) & 1) cout << "I" << '\n';
	else cout << "J" << '\n';
}

int T;

int main () {
	
	cin >> T;
	
	while (T --) Solve ();
	
	return 0;
}