#define _CRT_SECURE_NO_WARNINGS
#include <utility>
#include <string.h>
#include <string>
#include <math.h>
#include <stack>
#include <set>
#include <map>
#include <queue>
#include <deque>
#include <iterator>
#include <iostream>
#include <vector>
#include <algorithm>
#include <unordered_map>
#include <bitset>
#include <time.h>
#include <stdlib.h>

using namespace std;
const long long INF = 1ll << 32;
const double PI = acos(-1);
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<bool> vb;
typedef pair<int, int>pi;
typedef pair<ll, ll>pl;
typedef vector<pi>vpi;
typedef vector<pl>vpl;
typedef vector<vi> vvi;
typedef vector<vb> vvb;
typedef vector<vl> vvl;
typedef vector<string> vs;
int dc[] = { 0,0,1,-1 }, dr[] = { 1,-1,0,0 };
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define read(v) for (int it = 0; it < v.size(); it++) {scanf("%d", &v[it]);}
#define print(v) for(auto it : v) printf("%d ", it); puts("");
#define readL(v) for (int it = 0; it < v.size(); it++) scanf("%lld", &v[it]);
#define printL(v) for (auto it : v) printf("%lld ", it); puts("");
#define readC(v) for (int it = 0; it < v.size(); it++) {scanf("%c", &v[it]);}
#define printC(v) for(auto it : v) printf("%c ", it); puts("");

void build() {

}


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

	int t = 1;
	scanf("%d", &t);
	build();
	while (t--)
		solve();
	return 0;
}