/*
           _                   _         _       __  __  _____ 
     /\   | |            /\   | |       | |     |  \/  |/ ____|
    /  \  | |__   ___   /  \  | |__   __| | ___ | \  / | |     
   / /\ \ | '_ \ / _ \ / /\ \ | '_ \ / _` |/ _ \| |\/| | |     
  / ____ \| |_) | (_) / ____ \| |_) | (_| | (_) | |  | | |____ 
 /_/    \_\_.__/ \___/_/    \_\_.__/ \__,_|\___/|_|  |_|\_____|
 
*/

#include<bits/stdc++.h>
using namespace std;

#define F first
#define S second
#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(x) ((int)(x).size())

typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

const ld eps = 1e-9;
const int mod = 1e9 + 7;
const int oo = 1e9 + 7;
const ll lloo = 1e18 + 7;
const int N = 1e6 + 7;

void solve();

int main()
{
	// freopen("in","r",stdin);
	// freopen("out","w",stdout);
	int T = 1;
	scanf("%d",&T);
	while(T--) solve();
	return 0;
}

int n;
int a[N],b[N];

void solve()
{
	scanf("%d",&n);
	for(int i = 0 ; i < n ; i++) scanf("%d",a+i);
	for(int i = 0 ; i < n ; i++) scanf("%d",b+i);
	
	int ans = 0;
	for(int i = 0 ; i < n ; i++) {
		ans = max(ans,b[i]-a[i]);
	}
	
	printf("%d\n",ans);
}