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

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

void solve() {
    int n;
    cin >> n;
    vector<ll> a(n), b(n);
    for (auto& x : a) cin >> x;
    for (auto& x : b) cin >> x;
    sort(all(a));
    sort(all(b));
    ll ans = 0;
    rep(i,0,n) {
        rotate(begin(a), begin(a) + 1, end(a));
        ll mini = 5e9;
        rep(j,0,n) {
            mini = min(mini, abs(a[j] - b[j]));
        }
        ans = max(ans, mini);
    }
    cout << ans << '\n';
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    ll t; cin >> t; while(t--)
        solve();
}