You are given an array of integers a_i. Find the largest absolute value of difference between adjacent elements of the array max(abs(a_i - a_i + 1)).

The only line of the input contains a list of space-separated integers a_i (1 ≤ a_i ≤ 100) — elements of the array. The size of the array is between 2 and 10, inclusive. Note that the size of the array is not given explicitly!

Output a single integer — the largest absolute value of difference between adjacent elements of the array.