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

#define tsolve int t; cin >> t; while (t--) solve
#define all(x) ::begin(x), ::end(x)
#define sz(x) (ll)::size(x)

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

void solve() {
    int n;
    cin >> n;
    vector<ll> a(n), b(n);
    for (ll& e : a) cin >> e;
    for (ll& e : b) cin >> e;
    sort(all(a));
    sort(all(b));

    ll ans = 0;
    for (int off=0; off<n; off++) {
        ll mn = 1e18;
        for (int i=0; i<n; i++) {
            mn = min(mn, abs(a[i] - b[(i+off)%n]));
        }
        ans = max(ans, mn);
    }
    cout << ans << '\n';

}

int main() {
    cin.tie(0)->sync_with_stdio(false);
    cout << setprecision(16);
    tsolve();
}