Horse Racing Duals

A Hippodrome is organizing a new type of horse racing: duals. During a dual, only two horses will participate in the race. In order for the race to be interesting, it is necessary to try to select two horses with similar strength.

Write a solution which, using a given number of strengths, identify the two horses with the closest strengths and shows their difference with an integer (≥ 0).

Game Input

Input:

There are N horses. Array arr holds the strength Pi of each horse where Pi is an integer. The length of arr is N.

Output:

The difference D between the two closest strengths. D is an integer greater than or equal to 0.

Constraints:

1 < N < 100000
0 < Pi ≤ 10000000

Example

Input : [3, 5, 8, 9]
3 -> Which equals to N.
5 -> Which equals to Pi of first horse.
8 -> Which equals to Pi of second horse.
9 -> Which equals to Pi of third horse.

Output : 1
1 -> The difference between the two closest strengths (8 and 9)

Contributed by Erkan Ercan