#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll N = 10e5;
int x = 1;
void DGS()
{
  int n; cin>>n;
  vector<int> a(n) , b(n);
  for(auto &x : a) cin>>x;
  for(auto &y : b) cin>>y;

  int max = 0;
  for(int i=0;i<n;i++){
    int dif = b[i] - a[i];
    if(dif > max) max = dif;
  }
  cout<<max;
}

int main()
{
	ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
	ll n=1;
	cin>>n;
	while(n--) {DGS(); cout<<'\n';}
}