#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define all(x) x.begin(), x.end()

void solve(){
	int n;
	cin >> n;
	vector<int> a(n); 
	for(int i = 0, x; i<n; ++i){
		cin >> a[i];
	}
	int mx = 0;
	for(int i = 0, x; i<n; ++i){
		cin >> x;
		mx = max(mx, x - a[i]);
	}
	cout << mx << '\n';
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    cin >> t;
    while(t--){
    	solve();
    }
}