#include <stdio.h>
#include <stdlib.h>
 
long long inv;
int *B;
 
long long 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("%lld\n", inv);
 
  return 0;
}
 
long long countup(int *A, int p, int r)
{
  int q = p + (r-p)/2;
  int i, j, k, tmp;
  long long 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;
}