Life Transfer
Life Transfer
Note: “feli” is the local currency.
In the great city of Nekoresti, there are n people for which we know their ages: ai
is the age of the i-th person. Currently, they are on vacation, so they decided to go on a trip to Pisiev to visit a Koshkseum, a famous museum. They can go either by car or by motorcycle:
- a car can transport k people (one driver which has to be at least
lc
years old and k - 1 passengers). The cost to rent a car ispc
feli. - a motorcycle can transport only one person (which has to be at least
lm
years old). The cost to rent a motorcycle ispm
feli.
Unfortunately, people have money issues, so they decided to consult Mewlin, the great local magician from the city. Using a formidable spell called Mucadabra, Mewlin can transfer age from one person to another. Formally, he can reduce the age x of a person and increase the age y of another person by the same amount (so the sum of ages is constant). The cost to transfer 1 unit of age is t feli. For magic medical reasons, the age of a person cannot be changed by more than d years (if the initial age is x, his age must be at least x - d and at most x + d at all times). Also, the age cannot go below 1 year old.
Help the people from Nekoresti to spend as little money as possible, so they can arrive in Pisiev.
Input
The first line contains two integers n and k (1 ≤ n, k ≤ 105
) - the number of people and the maximum number of people that can be in one car.
The second line contains four integers lc
, pc
, lm
and pm
(1 ≤ lm
< lc
≤ 105
, 1 ≤ pm
< pc
≤ 105
) - the minimum needed age to drive a car; the price of renting one car; the minimum needed age to drive a motorcycle and the price of renting one motorcycle.
The third line contains two integers t and d (0 ≤ t, d ≤ 105
) - the price of transferring one year and the maximum number of times the spells can be applied per each person.
The fourth line contains n integers a1
, a2
, ..., an
(1 ≤ ai
≤ 105
) - the age of the i-th person.
Output
Print one number, the smallest amount of feli the people need to spend in order for them to reach their destination. If there is no such solution, print -1.
2 2 18 1000 16 1 5 3 16 15
1010
2 2 23 10 15 5 2 2 9 20
-1