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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
	final static int ICE_TEA_COUNT = 4;
	final static double SHORT_TEA = 0.25;
	public static void main(String[] args)throws Exception {
		BufferedReader br = new BufferedReader ( new InputStreamReader(System.in));
		String [] input = br.readLine().split(" ");
		String  input2 = br.readLine();
		long [] iceTeaList = new long[4];
		for(int i = 0;i<ICE_TEA_COUNT ;i++) {
			iceTeaList[i] = Integer.parseInt(input[i]);
		}

		int max = Integer.parseInt(input2);
		long [] resultTea = new long[4];
		int multiple = 2;
		long beforeResult = 1;
		boolean continueFlag = false;
		int point = 0;
		resultTea[0] = (long)( max / SHORT_TEA);
		for(int i = 0;i<ICE_TEA_COUNT-1 ;i++) {
			if(beforeResult == 0) {
				continueFlag = true;
			}else if(iceTeaList[i+point]*multiple > iceTeaList[i+1]) {
				resultTea[i+1] = resultTea[i+point]/multiple;
				resultTea[i+point] = resultTea[i+point]%multiple;
				continueFlag = false;
				point = 0;
				multiple = 2;
			}
			if(continueFlag) {
				point -= 1;
				multiple *=2;
				if(i+point >= 0) {
					beforeResult = (long)resultTea[i+point];
					i -= 1;
				}else {
					beforeResult = 1;
				}
			}else {
				beforeResult = resultTea[i+1];
			}
		}
		long resultValue=0;
		for(int i =0 ; i<ICE_TEA_COUNT;i++) {
			resultValue += resultTea[i] * iceTeaList[i];
		}
		System.out.println(resultValue);
	}
}