A company is responsible for constructing n electric poles for a city. The i-th electric pole has a height of hi. In order to maintain urban aesthetics, the city has imposed a regulation that the company will be charged a cost based on the height difference between two adjacent poles i and i+1, given by ci×|hi−hi+1|. Additionally, the height difference between two neighboring poles must not exceed d.
To meet these requirements, the company can increase the height of certain poles. However, increasing the height of the i-th pole by x units will incur a cost of x2. Find the minimum cost required to comply with the city's regulations.
### Input
- The first line contains two integer n,d.
- The second line contains n−1 integers ci with 1≤i≤n−1.
- The third line contain n integers hi.
### Output
- Print an integer, the minimum cost.
### Constraints
- 1≤n,d,hi≤5000.
- 1≤ci≤104.
### Example
Input:
54222223514
Output:
15