#include<iostream>
using namespace std;
#define MAXN 100005
long long merge(int A[],int left,int mid,int right)
{
	int i=left,j=mid,k=0;
	int temp[right-left+1];
	long long count=0;
	while(i<mid&&j<=right)
	{
		if(A[i]<=A[j]){
			temp[k++]=A[i++];
		}
		else{
			temp[k++]=A[j++];
			count+=mid-i;


		}
	}
	while(i<mid){
		temp[k++]=A[i++];
	}
	while(j<=right){
		temp[k++]=A[j++];
	}
	for(int i=left,k=0;i<=right;i++,k++){

	A[i]=temp[k];}

return count;
}
long long merge_sort(int A[],int left,int right){
	long long count=0;
	if(right>left){
		int mid=(left+right)/2;
		long long countleft=merge_sort(A,left,mid);
		long long countright=merge_sort(A,mid+1,right);
		long long mycount=merge(A,left,mid+1,right);
		return mycount+countleft+countright;
	}
	return count;
}
long long solve(int A[],int n)
{
	long long ans=merge_sort(A,0,n-1);
	return ans;
}
int main()
{
	int n,A[MAXN];
	cin>>n;
	for(int i = 0; i < n ; i++){
		cin>>A[i];
	}
	cout<<solve(A,n)<<endl;
}