Monocarp is playing a video game. In the game, he controls a spaceship and has to destroy an enemy spaceship.

Monocarp has two lasers installed on his spaceship. Both lasers $1$ and $2$ have two values:

• $p_i$ — the power of the laser;
• $t_i$ — the reload time of the laser.

When a laser is fully charged, Monocarp can either shoot it or wait for the other laser to charge and shoot both of them at the same time.

An enemy spaceship has $h$ durability and $s$ shield capacity. When Monocarp shoots an enemy spaceship, it receives $(P - s)$ damage (i. e. $(P - s)$ gets subtracted from its durability), where $P$ is the total power of the lasers that Monocarp shoots (i. e. $p_i$ if he only shoots laser $i$ and $p_1 + p_2$ if he shoots both lasers at the same time). An enemy spaceship is considered destroyed when its durability becomes $0$ or lower.

Initially, both lasers are zero charged.

What's the lowest amount of time it can take Monocarp to destroy an enemy spaceship?

Input

The first line contains two integers $p_1$ and $t_1$ ($2 \le p_1 \le 5000$; $1 \le t_1 \le 10^{12}$) — the power and the reload time of the first laser.

The second line contains two integers $p_2$ and $t_2$ ($2 \le p_2 \le 5000$; $1 \le t_2 \le 10^{12}$) — the power and the reload time of the second laser.

The third line contains two integers $h$ and $s$ ($1 \le h \le 5000$; $1 \le s < \min(p_1, p_2)$) — the durability and the shield capacity of an enemy spaceship. Note that the last constraint implies that Monocarp will always be able to destroy an enemy spaceship.

Output

Print a single integer — the lowest amount of time it can take Monocarp to destroy an enemy spaceship.

见题面 Input 部分

见题面 Output 部分

In the first example, Monocarp waits for both lasers to charge, then shoots both lasers at $10$, they deal $(5 + 4 - 1) = 8$ damage. Then he waits again and shoots lasers at $20$, dealing $8$ more damage.

In the second example, Monocarp doesn't wait for the second laser to charge. He just shoots the first laser $25$ times, dealing $(10 - 9) = 1$ damage each time.