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.

Constraints

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

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.

Examples

Input

4
2 3 7 9

Output

7

Input

8
3 1 4 1 5 9 2 6

Output

8

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