#include <bits/stdc++.h>

using namespace std;

vector<int> a, b, c;

void solve(){
    int n;

    cin >> n;

    a = b = vector(n, 0);
    c.clear();

    for(auto &x : a) cin >> x;
    for(auto &x : b) cin >> x;
    sort(a.begin(), a.end());
    sort(b.begin(), b.end());
    int res = 0;
    for(int i = 0;i <= n;i++){
        int now = 1e9;
        for(int j = 0; j < n; j++){
            now = min(now, abs(a[j] - b[j]));
        }
        res = max(res, now);
        vector<int>tmp;
        for(int j = 1;j < n;j++){
            tmp.push_back(a[j]);
        }
        tmp.push_back(a[0]);
        a = tmp;
    }
    cout << res << endl;
}

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

    int t = 1;

    cin >> t; // comment if not multitest

    while(t--) solve();
}