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

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

signed main()
{
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);
    int t; cin >> t;
    rep(task,0,t) {
        int n; cin >> n;
        vi valsa(n);
        vi valsb(n);
        rep(i,0,n) cin >> valsa[i];
        rep(i,0,n) cin >> valsb[i];
        sort(all(valsa));
        sort(all(valsb));

        int best = 0;
        rep(sep, 0, n) {
            int curr = -1;
            rep(i,0,n) {
                int diff = abs(valsa[i] - valsb[(i+sep)%n]);
                if (curr == -1 || diff < curr) {
                    curr = diff;
                }
            }
            best = max(curr, best);
        }

        cout << best << endl;
    }
    return 0;
}