Problem:
Score : 300 points

Problem Statement

You've come to your favorite store Infinitesco to buy some ice tea.

The store sells ice tea in bottles of different volumes at different costs.
Specifically, a 0.25-liter bottle costs Q yen, a 0.5-liter bottle costs H yen, a 1-liter bottle costs S yen, and a 2-liter bottle costs D yen.
The store has an infinite supply of bottles of each type.

You want to buy exactly N liters of ice tea. How many yen do you have to spend?

Constraints

1 \leq Q, H, S, D \leq 10^8

1 \leq N \leq 10^9

All input values are integers.

Input

Input is given from Standard Input in the following format:

Q H S D
N

Output

Print the smallest number of yen you have to spend to buy exactly N liters of ice tea.

Sample Input 1

20 30 70 90
3

Sample Output 1

150

Buy one 2-liter bottle and two 0.5-liter bottles. You'll get 3 liters for 90 + 30 + 30 = 150 yen.

Sample Input 2

10000 1000 100 10
1

Sample Output 2

100

Even though a 2-liter bottle costs just 10 yen, you need only 1 liter.
Thus, you have to buy a 1-liter bottle for 100 yen.

Sample Input 3

10 100 1000 10000
1

Sample Output 3

40

Now it's better to buy four 0.25-liter bottles for 10 + 10 + 10 + 10 = 40 yen.

Sample Input 4

12345678 87654321 12345678 87654321
123456789

Sample Output 4

1524157763907942

Solution in Scala (2.13.1) (judge verdict: Accepted)

object Main extends App {
  
  val sc = new java.util.Scanner(System.in)
  val prices = Map(
    0.25d -> sc.nextLong(),
    0.5d -> sc.nextLong(),
    1d -> sc.nextLong(),
    2d -> sc.nextLong()
  )
  val n = sc.nextLong()
  val cosp = prices.map{ case (s, p) => (s, (p / s).toLong)}.toList.sortBy(_._2).map(_._1)
  val ans = cosp.foldLeft((n, 0L))((rc, key) => {
    key match {
      case 2.0d if rc._1 >= 2 => ((rc._1 % key).toLong, rc._2 + ((rc._1 / key).toLong * prices(key)).toLong)
      case 2.0d if rc._1 < 2 => rc
      case _ => (0L, rc._2 + (rc._1 / key).toLong * prices(key))
    }
  })
  println(ans._2)
}