import java.io.*;

import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
import java.util.function.*;
import java.util.stream.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int q = in.nextInt();
        for(int a0 = 0; a0 < q; a0++){
            int n = in.nextInt();
            int[][] M = new int[n][n];
            for(int M_i=0; M_i < n; M_i++){
                for(int M_j=0; M_j < n; M_j++){
                    M[M_i][M_j] = in.nextInt();
                }
            }
            int k=0;
            int count1=0;
            int count=0;
             List<Integer> l1=null;
                    List<Integer> l2=null;
            // your code goes here
            for(int i=0;i<n-1;i++){
                if(k<(n-1))
                   for(int j=0;j<n;j++){
                   l1=new ArrayList<Integer>(M[k][j]);
                     l2=new ArrayList<Integer>(M[k+1][j]);
                    
                   
                
               }
                 int sum1=l1.stream().mapToInt(Integer::intValue).sum();
                    int sum2=l2.stream().mapToInt(Integer::intValue).sum();
                if((sum1==sum2)){
                    count++;
                }k++;
                   
                
            }
            
            k=0;
            
            
            
            for(int i=0;i<n-1;i++){
                 if(k<(n-1))
                for(int j=0;j<n;j++){
                  l1=new ArrayList<Integer>(M[j][k]);
                  l2=new ArrayList<Integer>(M[j][k+1]);
                    
                   
                
               }
                 int s1=l1.stream().mapToInt(Integer::intValue).sum();
                    int s2=l2.stream().mapToInt(Integer::intValue).sum();
                if((s1==s2)){
                    count1++;
                }else{count1--;} 
                k++;
              
            }
            
            if(count==count1){System.out.println("Possible");}
            else{System.out.println("Impossible");}
            
            
            
            
            
            
            
            
            
            
            
            
            
        }
    }
}