Problem Statement

You are given an integer sequence $A$ of length $N$. Find the maximum absolute difference of two elements (with different indices) in $A$.

Constraints

• $2 \leq N \leq 100$
• $1 \leq A_i \leq 10^9$
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N

Output

Print the maximum absolute difference of two elements (with different indices) in $A$.