Minimum Maximum Skill Difference

You are given T test cases. In each test case, there are N participants with given skill levels. Your task is to compute the minimum possible value of the maximum skill difference when comparing two adjacent players after sorting the skills in non-decreasing order.

In other words, for each test case you should:

• Sort the list of skill levels.
• Find the minimum difference between any two consecutive elements.

This minimum difference is the answer for that test case.

Note: The input is given from stdin and the output should be printed to stdout.

inputFormat

The first line contains an integer T denoting the number of test cases.

Then for each test case, the input is as follows:

• The first line contains an integer N – the number of participants.
• The second line contains N space separated integers representing the skill levels.

outputFormat

For each test case, output a single line containing the minimum value among the differences between any two adjacent skill levels in the sorted order.

## sample

2
4
1 5 3 9
6
8 1 7 4 6 2

2
1

</p>