#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 x; cin >> x; s.insert(x); } if (s.size() < 2) { cout << "NO" << endl; } else { auto it = s.begin(); it++; cout << *it << endl; } } return 0; }