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)

fun main(args: Array<String>) {
    val (q, h, s, d) = readLine()!!.split(" ").map(String::toLong)
    val n = readLine()!!.toLong()
    var qq = 4 * n
    var hq = 0L
    var sq = 0L
    var dq = 0L

    if (2 * q >= h && qq >= 2) {
        hq = qq / 2
        qq -= (qq / 2) * 2
    }

    if (2 * h >= s && hq >= 2) {
        sq = hq / 2
        hq -= (hq / 2) * 2
    }

    if (4 * q >= s && qq >= 4) {
        sq = qq / 4
        qq -= (qq / 4) * 4
    }

    if (2 * s >= d && sq >= 2) {
        dq = sq / 2
        sq -= (sq / 2) * 2
    }

    if (4 * h >= d && hq >= 4) {
        dq = hq / 4
        hq -= (hq / 4) * 4
    }

    if (8 * q >= d && qq >= 8) {
        dq = qq / 8
        qq -= (qq / 8) * 8
    }
    
    println(q * qq + h * hq + s * sq + d * dq)
}