#include <iostream>
#include <bits/stdc++.h>

using namespace std;

int main() {
    int t;
    cin >> t;
    while(t--) {
        int n;
        cin >> n;
        vector <int> a;
        a.resize(n);
        for(int i = 0; i < n; i++) {
            cin >> a[i];
        }

        vector <int> b;
        b.resize(n);
        for(int i = 0; i < n; i++) {
            cin >> b[i];
        }

        sort(a.begin(), a.end());
        sort(b.begin(), b.end());

        int globalmax = 0;
        for(int i = 0; i < n; i++) {
            int localmin = INT_MAX;
            int s1 = i + 1;
            int s2 = n - i - 1;
            for(int j = 0; j <= i; j++) {
                localmin = min(localmin, abs(a[j] - b[j + s2]));
            }

            for(int j = i + 1; j < n; j++) {
                localmin = min(localmin, abs(a[j] - b[j - s1]));
            }

            globalmax = max(globalmax, localmin);
        }

        cout << globalmax << endl;
    }
    return 0;
}