#include <bits/stdc++.h>

using namespace std;
const int c=5005;
int n, a[c], b[c];
void solve() {
    cin >> n;
    for (int i=0; i<n; i++) cin >> a[i];
    for (int i=0; i<n; i++) cin >> b[i];
    sort(a, a+n), sort(b, b+n);
    int ans=0;
    for (int i=0; i<n; i++) {
        int mini=2e9;
        for (int j=0; j<n; j++) {
            mini=min(mini, abs(a[j]-b[(i+j)%n]));
        }
        ans=max(ans, mini);
    }
    //cout << "valasz.......... ";
    cout << ans << "\n";
}
int main()
{
    ios_base::sync_with_stdio(false);
    int w;
    cin >> w;
    while (w--) {
        solve();
    }
    return 0;
}
/*
4
3
0 0 0
1000000000 1000000000 1000000000
5
1 2 3 4 5
1 2 3 4 5
6
0 0 0 100 100 100
100 100 100 0 0 0
7
14 25 62 74 86 95 12
51 62 71 72 92 20 84
*/