Problem Statement

It is only six months until Christmas, and AtCoDeer the reindeer is now planning his travel to deliver gifts.
There are N houses along TopCoDeer street. The i-th house is located at coordinate a_i. He has decided to deliver gifts to all these houses.
Find the minimum distance to be traveled when AtCoDeer can start and end his travel at any positions.

Input

Input is given from Standard Input in the following format:
N
a_1 a_2 ... a_N

Output

Print the minimum distance to be traveled.

Constraints

• 1 ≤ N ≤ 100
• 0 ≤ a_i ≤ 1000
• a_i is an integer.

Sample Input 1

4
2 3 7 9

Sample Output 1

7

The travel distance of 7 can be achieved by starting at coordinate 9 and traveling straight to coordinate 2.
It is not possible to do with a travel distance of less than 7, and thus 7 is the minimum distance to be traveled.

Sample Input 2

8
3 1 4 1 5 9 2 6

Sample Output 2

8

There may be more than one house at a position.

见题面 Input 部分

见题面 Output 部分