#include <iostream>
using namespace std;
int main() {
	int T;
	cin >> T;
	for (int cnt = 1; cnt <= T; cnt++) {

		int R, C, K;
		cin >> R >> C >> K;

		cout << "Case #" << cnt << ": ";

		if (R * C - K == 1) {
			cout << "IMPOSSIBLE" << endl;
			continue;
		}

		cout << "POSSIBLE" << endl;
		int i;
		for (i = 1; i <= R*C - K; i++) {
			if (i <= C) {
				if (i == 1) {
					if (i == C)
						cout << "S";
					else
						cout << "E";
				}
				else if (i == C || i == R * C - K)
					cout << "W";
				else
					cout << "E";
			}
			else
				cout << "N";

			if (i % C == 0)
				cout << endl;
		}
		for (; i <= R * C; i++) {
			cout << "S";
			if (i % C == 0)
				cout << endl;
		}

	}

}