import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	static int prim(int a[][],int n){
		int max = 0;
		int i,j,k;
		int low[]=new int[n];
		boolean used[]=new boolean[n];
		
		for(i=0;i<n;i++){
			low[i]=a[0][i];
//			used[i]=false;
		}
        used[0]=true;		
		for(i=1;i<n;i++){
			j=0;
			while(used[j]){
				j++;
			}
			
			for(k=0;k<n;k++){
				if((!used[k])&&low[k]<low[j]){
					j=k;
				}
			}
			
			if(low[j]>max)
				max=low[j];
			used[j]=true;
			for(k=0;k<n;k++){
				if((!used[k])&&a[j][k]<low[k]){
					low[k]=a[j][k];
				}
			}
		}
		return max;
		
	}
	
	
	
	public static void main(String[] args) throws Exception, IOException {
		 BufferedReader in = new BufferedReader(new InputStreamReader(
                 System.in));
		 int a[][];
		int num=Integer.parseInt(in.readLine());
		while(num--!=0){
			int n=Integer.parseInt(in.readLine());
			a=new int[n][n];
			for(int index=0;index<n;index++){
				String str=in.readLine();
				String line[]=str.split(" ");
				for(int i=0;i<n;i++){
				a[index][i]=Integer.parseInt(line[i]);
				}
			}
			System.out.println(prim(a,n));
		}
		
		
	}
	
	
	

}