#include <bits/stdc++.h>
using namespace std;

using ll = long long int;
using ld = long double;

void solve(){
    int n;
    cin >> n;
    vector<ll> a(n), b(n);
    for(ll &i : a) cin >> i;
    for(ll &i : b) cin >> i;
    sort(a.begin(), a.end());
    sort(b.begin(), b.end());
    ll res = 0;
    for(int dec = 0; dec < n; dec++){
        ll mini = INT32_MAX;
        for(int i = 0; i < n; i++){
            mini = min(mini, abs(a[i]-b[(i+dec)%n]));
    //        cerr << mini << '\n';
        }
        res = max(res, mini);
    }
    cout << res << '\n';
}

int main() {
    int t;
    cin >> t;
    while(t--) solve();
    return 0;
}