#include<bits/stdc++.h>

using namespace std;

void solve(){
	int n; cin >> n;
	vector<int> a(n);
	vector<int> b(n);
	for(auto &x : a)cin >> x;
	for(auto &x : b)cin >> x;
	sort(a.begin(), a.end());
	sort(b.begin(), b.end());
	int ans = 0;
	for(int i = 0; i < n; ++i){
		int mx = 1 << 30;
		for(int j = 0; j < n; ++j){
			mx = min(mx, abs(a[j] - b[(j + i) % n]));
		}
		ans = max(ans, mx);
	}
	cout << ans << '\n';

}

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