#include <bits/stdc++.h>
#define pii pair <int, int>

using namespace std;

int a[5001], b[5001];

void solve() {
    int n;
    cin >> n;
    for(int i = 0; i < n; i++)
        cin >> a[i];
    for(int i = 0; i < n; i++)
        cin >> b[i];
    sort(a, a + n);
    sort(b, b + n);
    int max1 = 0, minpart;
    for(int j = 0; j < n; j++)
    {
        minpart = 2e9;
        for(int i = 0; i < n; i++)
            minpart = min(minpart, abs(a[i] - b[(i + j) % n]));
        max1 = max(max1, minpart);
    }

    cout << max1 << '\n';
}

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

#ifdef LOCAL
    freopen("test.in", "r", stdin);
    freopen("test.out", "w", stdout);
#else

#endif
    int T = 1;
    cin >> T;
    while(T--) {
        solve();
    }
    return 0;
}