import java.io.; import java.util.; import java.util.stream.*; import static java.util.stream.Collectors.toList;

class Result {

/*
 * Complete the 'organizingContainers' function below.
 *
 * The function is expected to return a STRING.
 * The function accepts 2D_INTEGER_ARRAY container as parameter.
 */

public static String organizingContainers(List<List<Integer>> container) {
    int n = container.size();
    int[] containerCapacity = new int[n];
    int[] typeCount = new int[n];

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            containerCapacity[i] += container.get(i).get(j); // total balls in container i
            typeCount[j] += container.get(i).get(j);         // total balls of type j
        }
    }

    Arrays.sort(containerCapacity);
    Arrays.sort(typeCount);

    return Arrays.equals(containerCapacity, typeCount) ? "Possible" : "Impossible";
}

}

public class Solution { public static void main(String[] args) throws IOException { BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in)); BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

    int q = Integer.parseInt(bufferedReader.readLine().trim());

    IntStream.range(0, q).forEach(qItr -> {
        try {
            int n = Integer.parseInt(bufferedReader.readLine().trim());

            List<List<Integer>> container = new ArrayList<>();

            IntStream.range(0, n).forEach(i -> {
                try {
                    container.add(
                        Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
                            .map(Integer::parseInt)
                            .collect(toList())
                    );
                } catch (IOException ex) {
                    throw new RuntimeException(ex);
                }
            });

            String result = Result.organizingContainers(container);

            try {
                bufferedWriter.write(result);
                bufferedWriter.newLine();
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    });

    bufferedReader.close();
    bufferedWriter.close();
}

}