Problem Statement

Given are $N$ integers $A_1,\\ldots,A_N$.

Find the sum of $|A_i-A_j|$ over all pairs $i,j$ such that $1\\leq i < j \\leq N$.

In other words, find $\\displaystyle{\\sum_{i=1}^{N-1}\\sum_{j=i+1}^{N} |A_i-A_j|}$.

Constraints

• $2 \\leq N \\leq 2 \\times 10^5$
• $|A_i|\\leq 10^8$
• $A_i$ is an integer.

Input

Input is given from Standard Input in the following format:

$N$ $A_1$ $\\ldots$ $A_N$

Output

Print the answer.

Sample Input 1

3
5 1 2

Sample Output 1

8

We have $|5-1|+|5-2|+|1-2|=8$.

Sample Input 2

5
31 41 59 26 53

Sample Output 2

176