# n=5 # k=10000 # # l=[99, 88, 77, 66, 55] # l=[99, 88, 77, 66, 55] n=int(raw_input()) l=map(int,raw_input().split()) k=int(raw_input()) def C(x): num=0 for i in xrange(n): num+= int(l[i]/x) return num >= k lb = 0 ub = 100 for i in xrange(5): mid = float(lb+ub)/2 if C(mid):lb=mid else:ub=mid print float(ub)