There are n stones, numbered 1, 2, ..., n. For each i (1 ≤ i ≤ n), the height of stone i is hi. There is a frog who is initially on stone 1. It will repeat the following action some number of times to reach stone n: if the frog is currently on stone i, jump to stone i + 1 or stone i + 2. Here, a cost of |hi − hj| is incurred, where j is the stone to land on.

Find the minimum possible total cost incurred before the frog reaches stone n.

Input

The first line contains number n (2 ≤ n ≤ 105). Second line contains integers h1, h2, ..., hn (1 ≤ hi ≤ 104).

Output

Print the minimum possible total cost for frog to reach stone n.