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 Kotlin (1.0.0) (judge verdict: Accepted)

//300
fun a019(args: Array<String>) {
    val (Q, H, S, D) = args[0].split(" ").map { it.toLong() }
    val N = args[1].toLong()
    var price: Long = 0

    if (D <= 2 * S && D <= 4 * H && D <= 8 * Q) {
        price += (N / 2) * D
        if (N % 2 == 1L) {
            if (S <= 2 * H && S <= 4 * Q) {
                price += S
            } else if (2 * H <= S && H <= 2 * Q) {
                price += 2 * H
            } else {
                price += 4 * Q
            }
        }
    } else if (2 * S <= D && S <= 2 * H && S <= 4 * Q) {
        price += N * S
    } else if (4 * H <= D && 2 * H <= S && H <= 2 * Q) {
        price += N * 2 * H
    } else {
        price += N * 4 * Q
    }
    println(price)
}

fun main(args: Array<String>) {
    a019(readLineList())
}

fun readLineList(): Array<String> {
    val lineList = mutableListOf<String>()
    while (true) {
        val line = readLine()
        if (line.isNullOrBlank()) {
            break
        } else {
            lineList.add(line!!)
        }
    }
    return lineList.toTypedArray()
}