#include<stdio.h>
void RSort(int *,int,int);
void Reverse(int *,int,int,int);
double sum=0;
int main()
{
  int i,n;
  int N[200000];
  
  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&N[i]);
  }

  RSort(N,0,n);

  /*for(i=0;i<n;i++){
    printf("%d ",N[i]);
  }
  */
  printf("%f\n",sum);

  return 0;
}

void RSort(int *A,int left,int right)
{
  int mid,temp;
  if(left+1<right){
    mid=(left+right)/2;
    RSort(A,left,mid);
    RSort(A,mid,right);
    Reverse(A,left,mid,right);
  }
}

void Reverse(int *A,int left,int mid,int right)
{
  int k,n1,n2,L[100000],R[100000],i,j,m=0;
  n1=mid-left;
  n2=right-mid;
  for(i=0;i<n1;i++){
    L[i]=A[left+i];
  }
  for(i=0;i<n2;i++){
    R[i]=A[mid+i];
  }
  L[n1]=1000000000;
  R[n2]=1000000000;
  i=0;
  j=0;
  for(k=left;k<right;k++){
    if(L[i]<R[j]){
      A[k]=L[i];
      i++;
    }
    else{
      A[k]=R[j];
      sum+=n1-i;
      j++;
    }
  }
}