write a go solution for Description:
You are playing a famous computer game (that just works) where you have various skills you can level up. Today, you focused on the "Smithing" skill. Your tactic is obvious: forging weapons from ingots and then melting them back to return the materials partially. For simplicity, every time you create an item, you get 1 experience point, and every time you melt an item, you also get 1 experience point.

There are n classes of weapons you can forge and m types of metal ingots.

You can create one weapon of the i-th class, spending a_i ingots of metal of the same type. Melting a weapon of the i-th class (which you crafted earlier) returns you b_i ingots of the type of metal it was made of.

You have c_j metal ingots of the j-th type, and you know that you can craft a weapon of any class from any metal type. Each combination of a weapon class and a metal type can be used any number of times.

What is the maximum total amount of experience you can earn by crafting and melting weapons?

Input Format:
The first line contains two integers n and m (1<=n,m<=10^6) — the number of weapon classes and metal types.

The second line contains n integers a_1,a_2,...,a_n (1<=a_i<=10^6), where a_i is the number of ingots you need to forge one weapon of the i-th class.

The third line contains n integers b_1,b_2,...,b_n (0<=b_i<a_i), where b_i is the number of ingots you return by melting one weapon of the i-th class you forged earlier.

The fourth line contains m integers c_1,c_2,...,c_m (1<=c_j<=10^9) — the number of ingots you have of the corresponding metal type.

Output Format:
Print one integer — the maximum total experience points you can gain by repeatedly forging and melting weapons.

Note:
In the first example, you can do the following:

1. craft one weapon of the 1-st class from the 1-st type of metal, spending 9 ingots;
2. melt that weapon, returning 8 ingots of the 1-st metal type;
3. again, craft and melt one weapon of the 1-st class from the 1-st metal type;
4. craft and melt one weapon of the 3-rd class from the 1-st metal type;
5. craft and melt one weapon of the 3-rd class from the 3-rd metal type;
6. craft and melt one weapon of the 4-th class from the 1-st metal type;
7. craft and melt one weapon of the 5-th class from the 3-rd metal type;. Output only the code with no comments, explanation, or additional text.