#include <iostream>
#include <string>
using namespace std;

int main() {

	int n, r, c, cnt = 0;
	while(cin >> n >> r >> c){
		if(n == 0) return n;
		cnt++;
		cout << "Test " << cnt << endl;
		int state[79][11][79];
		for(int i = 0; i < r; i++){
			for(int j = 0; j < n; j++){
				string s;
				cin >> s;
				for(int k = 0; k < c; k++){
					char c = s[k];
					if(c == '.') state[j][i][k] = 0;
					else state[j][i][k] = 1;
				}
			}
		}
		bool Can = true;
		for(int i = 0; i < n; i++){
			bool can = false;
			for(int ii = 0; ii < r*c; ii++){
				int j = ii/c;
				int k = ii%c;
				if(state[i][j][k] == 0) continue;
				bool chong = true;
				for(int jj = 0; jj < n; jj++){
					if(jj != i && state[jj][j][k] > 0){
						chong = false;
						break;
					}
				}
				if(chong){
					can = true;
					state[i][j][k] = 2;
					goto yigewanshi;
				}
			}
			for(int ii = 0; ii < r*c-1; ii++){
				int j = ii/c;
				int k = ii%c;
				if(state[i][j][k] == 0) continue;
				for(int ii_ = ii+1; ii_ < r*c; ii_++){
					int j_ = ii_/c;
					int k_ = ii_%c;
					if(state[i][j_][k_] == 0) continue;
					bool chong = true;
					for(int jj = 0; jj < n; jj++){
						if(jj != i && state[jj][j][k] > 0 && state[jj][j_][k_] > 0){
							chong = false;
							break;
						}
					}
					if(chong){
						can = true;
						state[i][j][k] = 2;
						state[i][j_][k_] = 2;
						goto yigewanshi;
					}
				}
			}
			yigewanshi:
			if(!can){
				Can = false;
				break;
			}
		}
		if(!Can){
			cout << "impossible" << endl;
			continue;
		}
		for(int i = 0; i < r; i++){
			for(int j = 0; j < n; j++){
				for(int k = 0; k < c; k++){
					int temp = state[j][i][k];
					if(temp == 0) cout << '.';
					if(temp == 1) cout << 'o';
					if(temp == 2) cout << '#';
				}
				cout << ' ';
			}
			cout << endl;
		}
	}

	return 0;
}