#include <bits/stdc++.h>

using namespace std;

#pragma GCC target("avx2")
#pragma GCC optimize("O3")

const int DIM = 1e4 + 5;

int a[DIM], b[DIM];

int myabs(int x) {
    return x > 0 ? x : -x;
}

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

    int t;
    cin >> t;

    while (t--) {
        int n;
        cin >> n;

        for (int i = 1; i <= n; ++i)
            cin >> a[i];
        for (int i = 1; i <= n; ++i)
            cin >> b[i];

        sort(a + 1, a + n + 1);
        sort(b + 1, b + n + 1);
        for (int i = 1; i <= n; ++i)
            b[i + n] = b[i];

        int mx = 0;
        for (int p = 1; p <= n; ++p) {
            int vl = 1e9;
            for (int p1 = 1, p2 = p; p1 <= n; ++p1, ++p2)
                vl = min(vl, myabs(a[p1] - b[p2]));

            mx = max(mx, vl);
        }

        cout << mx << "\n";
    }


    return 0;
}