#include <bits/stdc++.h> using namespace std; using ll = long long; const int maxn = (int)2e5+10; ll n, l[maxn], r[maxn]; void solve() { cin >> n; ll ans = 0; for(int i = 1; i <= n; i++) cin >> l[i]; for(int i = 1; i <= n; i++) cin >> r[i]; for(int i = 1; i < n; i++) ans+=min(l[i+1], r[i]); cout << ans << "\n"; } int main() { ios_base::sync_with_stdio(false); cin.tie(0); int t = 1; cin >> t; while(t--) solve(); return 0; }