#include <stdio.h>
#include <stdlib.h>

int inv;
int *B;

int countup(int *A, int p, int r);

int main(int argc, char *argv[])
{
  int n, i, j;
  int *A;

  inv = 0;

  scanf("%d", &n);
  A = (int *)malloc(sizeof(int) * n);
  B = (int *)malloc(sizeof(int) * n);
  for (i = 0; i < n; i++) scanf("%d", &A[i]);

  inv = countup(A, 0, n - 1);

  printf("%d\n", inv);

  return 0;
}

int countup(int *A, int p, int r)
{
  int q = p + (r-p)/2;
  int i, j, k, tmp;
  int ct = 0;

  if (r - p < 3) {
    for (i = p; i < r; i++) {
      for (j = r; j > i; j--) {
	if (A[j] < A[j-1]) {
	  tmp = A[j-1];
	  A[j-1] = A[j];
	  A[j] = tmp;
	  ct++;
	}
      }
    }
    return ct;
  }
  ct += countup(A, p, q);
  ct += countup(A, q+1, r);

  i = p;
  j = q + 1;
  for (k = p; k <= r; k++) {
    if (i >= q + 1 || j >= r + 1) {
      if (i >= q + 1) B[k] = A[j++];
      else B[k] = A[i++];
    } else {
      if (A[i] > A[j]) {
	B[k] = A[j];
	ct += q - i + 1;
	j++;
      } else {
	B[k] = A[i];
	i++;
      }
    }
  }
  for (k = p; k <= r; k++) A[k] = B[k];
  return ct;
}