#include <bits/stdc++.h>

//#pragma GCC optimize("O3")
//#define int long long

using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;

void solve(){
	int n;
	cin >> n;
	vector<int> a(n), b(n);
	for(int &x : a) cin >> x;
	for(int &x : b) cin >> x;
	sort(all(a)); sort(all(b));
	int sol = 0;
	for(int i = 0; i < n; i++){
		int cur = 1000000000;
		for(int j = 0; j < n; j++){
			int k;
			if(j+i >= n){
				k = j+i-n;
			} else k = i+j;
			cur = min(cur, max(a[j]-b[k], b[k]-a[j]));
		}
		sol = max(sol, cur);
	}
	cout << sol << "\n";
}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	int t;
	cin >> t;
	while(t--) solve();
}