Equal Chocolates

Christy is interning at HackerRank. One day she has to distribute some chocolates to her colleagues. She is biased towards her friends and plans to give them more than the others. One of the program managers hears of this and tells her to make sure everyone gets the same number.

To make things difficult, she must equalize the number of chocolates in a series of operations. For each operation, she can give  chocolates to all but one colleague. Everyone who gets chocolate in a round receives the same number of pieces.

For example, assume the starting distribution is . She can give  bars to the first two and the distribution will be . On the next round, she gives the same two  bar each, and everyone has the same number:.

Given a starting distribution, calculate the minimum number of operations needed so that every colleague has the same number of chocolates. 

Input Format

The first line contains an integer , the number of testcases.

Each testcase has  lines. 
- The first line contains an integer , the number of colleagues. 
- The second line contains n space-separated integers denoting the number of chocolates each colleague has.

Constraints

 
 
Number of initial chocolates each colleague has < 

Output Format

Print the minimum number of operations needed for each test case, one to a line.

Sample Input

1
4
2 2 3 7

Sample Output

2

Explanation

Start with  
Add  to all but the 3rd element  
Add  to all but the 4th element 

Two operations were required.

Sample Input 1

1
3
10 7 12

Sample Output 1

2

Explanation 1

Start with  
Add  to the first two elements  
Add  to the last two elements 

Two operations were required.