#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    int tc; cin >> tc;

    test:
    while (tc--) {
        ll n; cin >> n;
        
        ll a[n+1], b[n+1];
        for (ll i = 1; i <= n; i++) cin >> a[i];
        for (ll i = 1; i <= n; i++) cin >> b[i];

        ll suffMx[n+2] = {0};
        for (ll i = n; i >= 1; i--) suffMx[i] = max(suffMx[i+1], b[i]);
        
        ll ans = 0;
        for (ll i = 1; i <= n; i++) ans += max(0LL, suffMx[i] - a[i]);
        cout << ans << "\n";
    }
}