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.util.Scanner;

class Main{
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		long Q=sc.nextLong();
		long H=sc.nextLong();
		long S=sc.nextLong();
		long D=sc.nextLong();
		
		long[] ichi_li=new long[3];
		long[] ni_li=new long[4];
		
		ichi_li[0]=Q*4;
		ichi_li[1]=H*2;
		ichi_li[2]=S;
		long ichi_saiyasu=Math.min(Math.min(ichi_li[0], ichi_li[1]), ichi_li[2]);
		
		ni_li[0]=Q*8;
		ni_li[1]=H*4;
		ni_li[2]=S*2;
		ni_li[3]=D;
		long ni_saiyasu=Math.min(Math.min(ni_li[0], ni_li[1]), Math.min(ni_li[2], ni_li[3]));
		
		long N=sc.nextLong();
		long sum=0;
		
		if(ichi_saiyasu*2>=ni_saiyasu) {
			System.out.println((N/2)*ni_saiyasu+(N%2)*ichi_saiyasu);
		}
		
		else if(ichi_saiyasu*2<ni_saiyasu) {
			System.out.println(N*ichi_saiyasu);
		}
	}
}