m = int(input()) for _ in range(m): n = int(input()) a = input().split() a = [int(x) for x in a] min = a[0] for i in range(1,n): if a[i]<min: min = a[i] #找到最小的存放在min min_sec = 1000 for i in range(n): if a[i]>min and a[i]<min_sec: min_sec = a[i] if min_sec == 1000: print("NO") else: print(min_sec)