Mirko discovered what Slavko did in the previous task, and decided to deal with something completely different from tables of letters: sequences of numbers.
Let's define a value of a sequence as the difference between the largest and the smallest number within that sequence. For example, value of sequence is , and value of is .
Find the sum of values of all subsequences of consecutive elements of a given sequence.
Input Specification
The first line of input contains a single integer , number of elements of the sequence. Next lines contain elements of the sequence. Each element is a positive integer not greater than .
Output Specification
The first and only line of output must contain the requested sum.
Sample Input 1
3
1
2
3
Sample Output 1
4
Sample Input 2
4
7
5
7
5
Sample Output 2
12
Sample Input 3
4
3
1
7
2
Sample Output 3
31
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