Description

Given a sequence with N integers A(1), A(2), ..., A(N), your task is to find out a sequence B(1), B(2), ..., B(N), such that

V = (|A(1) – B(1)| + |A(2) – B(2)| + ... + |A(N) – B(N)|) + (|B(1) – B(2)| + |B(2) – B(3)| + ... +|B(N-1) – B(N)|)

Input

The first line in the input contains an integer N (1 <= N <= 100). Then follow N lines, the i-th of which contains an integer A(i) (-10000 <= A(i) <= 10000).

Output

The output only contains an integer, which is the minimum value of V.

3
3
5
8

5

Source

,Minkerui