#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define ss second
#define ff first
#define pb push_back
#define mk make_pair
ll a[2000000],b[200100];
int main(){
    int t;
    cin>>t;
    while(t--){
        int n;
        ll ans=0;
        cin>>n;
        for(int i=0;i<n;i++)cin>>a[i];
        for(int i=0;i<n;i++){
            cin>>b[i];
            ans=max(ans,b[i]-a[i]);
        }
        cout<<ans<<endl;
    }
}