#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
    int tc;
    cin >> tc;

    while(tc--)
    {
        int n;
        cin >> n;

        vector <long long> sumaFila(n, 0);
        vector <long long> sumaColumna(n, 0);

        for(int i=0; i<n; i++)
        {
            for(int j=0; j<n; j++)
            {
                long long a;
                cin >> a;
                sumaFila[i] += a;
                sumaColumna[j] += a;
            }
        }

        sort(sumaFila.begin(), sumaFila.end());
        sort(sumaColumna.begin(), sumaColumna.end());

        bool posible = true;

        for(int i=0; i<n && posible; i++)
            if(sumaFila[i] != sumaColumna[i])
                posible = false;

        if(posible)
            cout << "Possible" << endl;
        else
            cout << "Impossible" << endl;
    }

    return 0;
}