question 69

import java.util.*;
import java.lang.*;
import java.io.*;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner sc = new Scanner(System.in);
		int x=sc.nextInt();
		while(x-->0) {
			int a=sc.nextInt();
			int b[]=new int[a];
			int c[]=new int[a];
			for(int i=0;i<a;i++) {
				b[i]=sc.nextInt();
			}
			for(int i=0;i<a;i++) {
				c[i]=sc.nextInt();
			}
			Arrays.sort(b);
			Arrays.sort(c);
			int m=a-1,sum=0,max=0;
			for(int i=0;i<a;i++) {
				sum=b[i]+c[m];
				if(max<=sum)
					max=sum;
				sum=0;
				m--;
			}
			System.out.println(max);
		}
	}

}