1. #include <bits/stdc++.h>
  2. using namespace std;
  3. using ll = long long;
  4. const int maxn = (int)2e5+10;
  5. ll n, l[maxn], r[maxn];
  6.  
  7. void solve()
  8. {
  9.     cin >> n; ll ans = 0;
  10.     for(int i = 1; i <= n; i++) cin >> l[i];
  11.     for(int i = 1; i <= n; i++) cin >> r[i];
  12.     for(int i = 1; i < n; i++) ans+=min(l[i+1], r[i]);
  13.     cout << ans << "\n";
  14. }
  15.  
  16. int main()
  17. {
  18.     ios_base::sync_with_stdio(false); cin.tie(0);
  19.     int t = 1; cin >> t; while(t--) solve(); return 0;
  20. }