#include<iostream>

#include<bits/stdc++.h>
typedef long long ll;
typedef long double ld;
const int mod=1e9+7;
const ll INF=1e18;
const double pi=3.14159265358979323846;

#define F first
#define S second
#define all(v) v.begin(),v.end()
#define pb push_back
#define Go ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

using namespace std;

ll a[200010],b[200010];

int main()
{
Go

int t; cin >> t;
while(t--)
{
    int n; cin >> n;
    for(int i=0;i<n;i++)cin >> a[i];
    for(int i=0;i<n;i++)cin >> b[i];

    ll ans=0;
    for(int i=0;i<n;i++)ans=max(ans,b[i]-a[i]);

    cout << ans << '\n';
}

return 0;
}