import java.io.IOException; import java.util.Arrays; import java.util.InputMismatchException; public class Main { int n; long[] s; long k; boolean check(double l) { long ans = 0; for (int i = 0; i < n; i++) { ans += (int) (s[i] / l); } return k <= ans; } void run() { MyScanner sc = new MyScanner(); n = sc.nextInt(); s = sc.nextLongArray(n); k = sc.nextLong(); Arrays.sort(s); double low = 0, high = s[n - 1]; for (int i = 0; i < 10000000; i++) { double mid = (low + high) / 2; if (check(mid)) { low = mid; } else { high = mid; } } System.out.println(low); } public static void main(String[] args) { new Main().run(); } public void mapDebug(int[][] a) { System.out.println("--------map display---------"); for (int i = 0; i < a.length; i++) { for (int j = 0; j < a[i].length; j++) { System.out.printf("%3d ", a[i][j]); } System.out.println(); } System.out.println("----------------------------" + '\n'); } class MyScanner { int read() { try { return System.in.read(); } catch (IOException e) { throw new InputMismatchException(); } } boolean isSpaceChar(int c) { return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } boolean isEndline(int c) { return c == '\n' || c == '\r' || c == -1; } int nextInt() { return Integer.parseInt(next()); } int[] nextIntArray(int n) { int[] array = new int[n]; for (int i = 0; i < n; i++) array[i] = nextInt(); return array; } long nextLong() { return Long.parseLong(next()); } long[] nextLongArray(int n) { long[] array = new long[n]; for (int i = 0; i < n; i++) array[i] = nextLong(); return array; } double nextDouble() { return Double.parseDouble(next()); } double[] nextDoubleArray(int n) { double[] array = new double[n]; for (int i = 0; i < n; i++) array[i] = nextDouble(); return array; } String next() { int c = read(); while (isSpaceChar(c)) c = read(); StringBuilder res = new StringBuilder(); do { res.appendCodePoint(c); c = read(); } while (!isSpaceChar(c)); return res.toString(); } String[] nextStringArray(int n) { String[] array = new String[n]; for (int i = 0; i < n; i++) array[i] = next(); return array; } String nextLine() { int c = read(); while (isEndline(c)) c = read(); StringBuilder res = new StringBuilder(); do { res.appendCodePoint(c); c = read(); } while (!isEndline(c)); return res.toString(); } } }