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

using ll=long long;
#define int ll
#define rep(i,a,b) for(int i=a;i<(b);i++)
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
using pii=pair<int,int>;
using vi=vector<int>;
#define fi first
#define se second
#define pb push_back

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    int t;
    cin>>t;
    while (t--)
    {
        int n;
        cin>>n;
        vector<int> v(n), u(n);
        for (int& i : v)
            cin>>i;
        for (int& i : u)
            cin>>i;

        sort(v.begin(), v.end());
        sort(all(u));

        int mx = 0;
        for (int i=0; i<n; i++)
        {
            int mn = 1e18;
            for (int j=i; j<n; j++)
                mn = min(mn, abs(u[j] - v[j-i]));
            for (int j=n-i; j<n; j++)
                mn = min(mn, abs(u[j-(n-i)]-v[j]));
            mx = max(mx, mn);
        }
        cout<<mx<<"\n";
    }

}