[백준] 10707번 : 수도요금 - Python(파이썬)

https://www.acmicpc.net/problem/10707

a=int(input())
b=int(input())
c=int(input())
d=int(input())
p=int(input())
sum=p*a
sum1=0
if p<=c: sum1=b
else: sum1=b+(p-c)*d
print(min(sum,sum1))