#include<bits/stdc++.h>
using namespace std;
#define int             long long
#define pb              push_back
#define endl            '\n'
#define ff              first
#define ss              second
#define debug           cout<<"HERE"<<endl;
void edm()
{
    ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);
    #ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    freopen("outputtt.txt","w",stdout);
    #endif
}
void solve()
{
    int n;cin>>n;
    int arr[n+1],brr[n+1];
    for(int i=1;i<=n;i++)cin>>arr[i];
    for(int i=1;i<=n;i++)cin>>brr[i];
    for(int i=n-1;i>0;i--)
    {
        brr[i] = max(brr[i],brr[i+1]);
    }
    int ans=0;
    for(int i=1;i<=n;i++)
    {
        int v1 = arr[i];
        int v2 = brr[i];
        if(v2>v1)
        {
            ans = ans + (v2-v1);
        }
    }
    cout<<ans<<endl;
}
int32_t main()
{
    //edm();
    int t = 1;
    cin>>t;
    for(int i=1;i<=t;i++)
    {
        // cout<<"Case "<<i<<": ";
        solve();
    }
}