180. Inversions

time limit per test: 0.25 sec / memory limit per test: 4096 KB

There are N integers (1<=N<=65537) A1, A2,.. AN (0<=Ai<=10^9). You need to find amount of such pairs (i, j) that 1<=i<j<=N and A[i]>A[j].

Input

The first line of the input contains the number N. The second line contains N numbers A1…AN.

Output

Write amount of such pairs.

Example(s)

Sample Input	Sample Output
5 2 3 1 5 4	3