There are n stones, numbered from 1 to n. For each i (1≤i≤n), the height of the i-th stone is hi. The frog initially sits on stone 1. It repeats the following action several times to reach stone n: if the frog is on stone i, it can jump either to stone i+1 or to stone i+2. The cost of moving from the i-th to the j-th stone is ∣hi−hj∣.
Find the minimum cost of moving the frog to stone n.
The first line contains the number of stones n (2≤n≤105). The second line contains integers h1,h2,...,hn (1≤hi≤104).
Print the minimum cost of moving the frog to stone n.