#include <bits/stdc++.h>
using namespace std;
int main() {
int t; cin >> t;
while (t--) {
int n; cin >> n;
vector<int>v1(n), v2(n);
for (int i = 0; i < n; i++)
cin >> v1[i];
for (int i = 0; i < n; i++)
cin >> v2[i];
int ans = 0, d = 0;
for (int i = 0; i < n; i++) {
d = v1[i] - v2[i];
if(d < 0)
ans = max(ans, abs(d));
}
cout << ans << endl;
v1.clear();
v2.clear();
}
}