Problem Statement

There are $N stones, numbered 1, 2, \ldots, N$.
For each $i (1 \leq i \leq N)$, the height of Stone i is h_i.
Here, $h_1 < h_2 < \cdots < h_N$ holds.
There is a frog who is initially on Stone 1.
He will repeat the following action some number of times to reach Stone N:

• If the frog is currently on Stone i, jump to one of the following: Stone $i + 1, i + 2, \ldots, N. Here, a$ cost of (h_j - h_i)^2 + C is incurred, where j is the stone to land on.

Find the minimum possible total cost incurred before the frog reaches Stone N.

Input

Input is given from Standard Input in the following format:
N C
$h_1 h_2 \ldots h_N$

Output

Print the minimum possible total cost incurred.

Constraints

• All values in input are integers.
• $2 \leq N \leq 2 \times 10^5$
• $1 \leq C \leq 10^{12}$
• $1 \leq h_1 < h_2 < \cdots < h_N \leq 10^6$

Sample Input 1

5 6
1 2 3 4 5

Sample Output 1

20

If we follow the path 1 → 3 → 5, the total cost incurred would be ((3 - 1)^2 + 6) + ((5 - 3)^2 + 6) = 20.

Sample Input 2

2 1000000000000
500000 1000000

Sample Output 2

1250000000000

The answer may not fit into a 32-bit integer type.

Sample Input 3

8 5
1 3 4 5 10 11 12 13

Sample Output 3

62

If we follow the path 1 → 2 → 4 → 5 → 8, the total cost incurred would be ((3 - 1)^2 + 5) + ((5 - 3)^2 + 5) + ((10 - 5)^2 + 5) + ((13 - 10)^2 + 5) = 62.

见题面 Input 部分

见题面 Output 部分