package main

import (
  "fmt"
)

func main() {
  var n int
  fmt.Scan(&n)
  l := make([]int, n)
  for i := 0; i < n; i++ {
    fmt.Scan(&l[i])
  }
  var k int
  fmt.Scan(&k)

  lb := 0.0
  ub := 1000000000.0
  for i := 0; i < 100; i++ {
    mid := (lb + ub) / 2.0
    c := 0
    for j := 0; j < n; j++ {
      c += int(float64(l[j]) / mid)
    }
    if c >= k {
      lb = mid
    } else {
      ub = mid
    }
  }
  fmt.Println(lb)
}