#include <bits/stdc++.h>

using namespace std;

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    int T;
    cin >> T;
    while (T--) {
        int n;
        cin >> n;
        auto a = vector<int>(n);
        auto b = vector<int>(n);
        for (int &x : a) cin >> x;
        for (int &x : b) cin >> x;
        std::sort(a.begin(), a.end());
        std::sort(b.begin(), b.end());

        int best = 0;
        for (int offset = 0; offset != n; ++offset) {
            int val = 2e9;
            for (int i = 0; i != n; ++i) {
                int j = i + offset;
                if (j >= n) j -= n;
                val = min(val, abs(a[i] - b[j]));
            }
            best = max(best, val);
        }
        cout << best << '\n';
    }
}