Piglet lying on the lawn watched the swaying grass. He realized that they were swaying because the wind was blowing and then he came up with an idea how to measure the strength of the wind with the help of grass. The wind strength, by definition of Piglet, is the difference between the height of the highest and lowest grass.

Input

First line contains one number n - the number of observed grass by Piglet. The next line contains n numbers - the heights of the grass blades.

All input data are positive integers not exceeding 100, as Piglet does not like to count much and could not do it for a very simple reason - he had never met numbers larger than 100 in his life.

Output

Print one number - the strength of the wind by the definition of Piglet.