#include <iostream>
using namespace std;

int t, n, a[200000], b[200000], ans[10000];

int main()
{
    cin >> t;
    for (int i = 0; i < t; i++){
        cin >> n;
        for (int j = 0; j < n; j++){
            cin >> a[j];
        }
        for (int k = 0; k < n; k++){
            cin >> b[k];
            if (b[k] - a[k] > ans[i]){
                ans[i] = b[k] - a[k];
            }
        }
    }
    
    for (int i = 0; i < t; i++){
        cout << ans[i] << "\n";
    }
    return 0;
}