#include <bits/stdc++.h>
using namespace std;
const int N = 5005;

int t, n;

int solve(vector<int>& x, vector<int>& y) {
    int ret = 1e9;
    for (int i = 0; i < n; ++i) {
        ret = min(ret, abs(x[i] - y[i]));
    }
    return ret;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);

    cin >> t;
    while (t--) {
        cin >> n;
        vector<int> a (n);
        for (int i = 0; i < n; ++i) cin >> a[i];
        vector<int> b (n);
        for (int i = 0; i < n; ++i) cin >> b[i];
        sort(a.begin(), a.end());
        sort(b.begin(), b.end());
        int ans = 0;
        for (int i = 0; i < n; ++i) {
            ans = max(ans, solve(a, b));
            vector<int> t = {};
            for (int j = 1; j < n; ++j) t.push_back(a[j]);
            t.push_back(a[0]);
            swap(a, t);
        }
        cout << ans << "\n";
    }
    return 0;
}