#include <bits/stdc++.h>
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;

#define pb push_back
#define ff first
#define ss second

void solve(){
	ll n; cin>>n;
	
	vector<ll> a(n), b(n);
	
	for(ll &u: a) cin>>u;
	for(ll &u: b) cin>>u;
	
	sort(all(a));
	sort(all(b));
	
	ll ans=0;
	
	rep(o,0,n){
		ll cur=1e9;
		
		rep(i,0,n){
			cur=min(cur, abs(a[i]-b[(i+o)%n]));
		}
		ans=max(ans, cur);
	}
	
	cout<<ans<<'\n';
}

int main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);
	cout<<fixed<<setprecision(12);
	
	ll t; cin>>t;
	
	while(t--){ solve();}
}