Tired of the overpopulated world, Miu - The introverted cat visits a new continent in search for a new house.  
There are $N$ houses lying on the X-axis.
Their positions are given by $X$$i$ , where $i$ refers to the $i$th house. ( $1 <= i <= N$ )
Each of these positions are pairwise distinct 
Miu is supposed to choose one of these houses for herself.
Miu defines a term - The Distance of Peace,  as the minimum distance from her house to any other house.  
Miu wonders what is maximum Distance of Peace she can obtain. Can you help her?
-----Input:-----
- The first line of the input consists of a single integer $T$, denoting the number of test cases  
- The first line of each test case consists of a single integer $N$ 
- The second line of each test case consists of $N$ space-separated integers
$X$$1$ $X$$2$ $X$$3$ … $X$$N$
-----Output:-----
- For each test case print the answer in a single line, the maximum Distance of Peace Miu can obtain
-----Constraints-----
- 1 <= $T$ <= 100  
- 2 <= $N$ <= 105 
- -109 <= $X$$i$ <= 109 
- Sum of $N$ over all test cases does not exceed 106 
-----Subtasks-----
Subtask #1 (30 points): 
- $N$ <= 103 
Subtask #2 (70 points): 
- Original Constraints
-----Sample Input:-----
2
6
7 -1 2 13 -5 15
4
6 10 3 12  
-----Sample Output:-----
5
3  
-----EXPLANATION:-----
Test Case 1:
The $1$st house has the maximum Distance of Peace, which is from the $3$rd house:
$| 7 - 2 | = 5$
Hence, the answer is $5$
t=int(input())
while(t>0):
 n=int(input())
 l=list(map(int,input().split()))
 l.sort()
 m=list()
 m.append(abs(l[0]-l[1]))
 m.append(abs(l[-1]-l[-2]))
 for i in range(1,n-1,1):
  if(abs(l[i]-l[i-1])<abs(l[i]-l[i+1])):
   m.append(abs(l[i]-l[i-1]))
  else:
   m.append(abs(l[i]-l[i+1]))
 print(max(m))
 t-=1
t=int(input())
while(t>0):
 n=int(input())
 l=list(map(int,input().split()))
 l.sort()
 m=list()
 m.append(abs(l[0]-l[1]))
 m.append(abs(l[-1]-l[-2]))
 for i in range(1,n-1,1):
  if(abs(l[i]-l[i-1])<abs(l[i]-l[i+1])):
   m.append(abs(l[i]-l[i-1]))
  else:
   m.append(abs(l[i]-l[i+1]))
 print(max(m))
 t-=1