#include <iostream> #include <set> using namespace std; int main() { int C; cin >> C; while (C--) { int n; cin >> n; set<int> s; for (int i = 0; i < n; ++i) { int num; cin >> num; s.insert(num); } if (s.size() < 2) { cout << "NO" << endl; } else { auto it = s.begin(); advance(it, 1); cout << *it << endl; } } return 0; }