#include <bits/stdc++.h>

using namespace std;


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

    int t;
    cin >> t;
    while (t--)
    {
        int n;
        cin >> n;
        vector<int> a(n), b(n);
        for (int i=0;i<n;i++)
            cin >> a[i];
        for (int i=0;i<n;i++)
            cin >> b[i];
        sort(a.begin(), a.end());
        sort(b.begin(), b.end());
        for (int i=0;i<n;i++)
            b.push_back(b[i]);
        int ans = 0;
        for (int i=0;i<n;i++)
        {
            int minim = abs(a[0]-b[i]);
            for (int j=0;j<n;j++)
                minim = min(minim, abs(a[j]-b[j+i]));
            ans = max(ans, minim);
        }
        cout << ans << '\n';
    }
    return 0;
}