#include "bits/stdc++.h" #define ALL(obj) (obj).begin(),(obj).end() #define RALL(obj) (obj).rbegin(),(obj).rend() #define REP(i, n) for(int i = 0; i < (int)(n); i++) #define REPR(i, n) for(int i = (int)(n); i >= 0; i--) #define FOR(i,n,m) for(int i = (int)(n); i < int(m); i++) using namespace std; typedef long long ll; const int MOD = 1e9 + 7; const int INF = MOD - 1; const ll LLINF = 4e18; int n; vector L; ll k; // 長さmの棒を作れるか bool f(double m) { ll cnt = 0; REP(i, n) { cnt += int(L[i] / m); } if (cnt >= k) { return true; } return false; } int main() { cin >> n; L.resize(n); REP(i, n) cin >> L[i]; cin >> k; double l = 0, r = 1e9+1; REP(i,100) { double mid = r - (r - l) / 2; if (f(mid)) { l = mid; } else { r = mid; } } printf("%.10f", l); getchar(); getchar(); }