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 Python (3.8.2) (judge verdict: Wrong Answer)

Q,H,S,D=map(int,input().split())

def buy(x,y):  #残りｘリットルでy円
    if y=='D':
        return (x//2)*D,x%2
    elif y=='S':
        return (x//1)*S,x%1
    elif y=='H':
        return (x//0.5)*H,x%0.5
    elif y=='Q':
        return (x//0.25)*Q,x%0.25  #かかる金額と残量
    
dic={'Q':4*Q,'H':2*H,'S':S,'D':D/2}


n=int(input())
ans=0
for i in range(4):
    key=min(dic, key=dic.get)
    dic.pop(key)
    x,y=buy(n,key)
    ans+=x
    n=y
    if n==0:
        break

print(int(ans))