#include <bits/stdc++.h>
#include<algorithm>
using namespace std;
int a[100010];
int b[100010];
void Merge(int a[],int s,int m,int e,int tmp[])
{
int pb=0;
int p1=s,p2=m+1;
while(p1<=m&&p2<=e){
if(a[p1]>a[p2])
tmp[pb++]=a[p1++];
else
tmp[pb++]=a[p2++];
}
while(p1<=m)
tmp[pb++]=a[p1++];
while(p2<=e)
tmp[pb++]=a[p2++];
for(int i=0;i<e-s+1;i++)
a[s+i]=tmp[i];
}
long long Count(int a[],int s,int m,int e)
{
long long result=0;
int p1=s,p2=m+1;
while(p1<=m&&p2<=e){
if(a[p1]>a[p2]){
result+=e-p2+1;
++p1;
}
else
++p2;
}
return result;
}
long long MergeSort(int a[],int s,int e,int tmp[])
{
long long result=0;
if(s<e){
int m=s+(e-s)/2;
result+=MergeSort(a,s,m,tmp);
result+=MergeSort(a,m+1,e,tmp);
result+=Count(a,s,m,e);
Merge(a,s,m,e,tmp);//从大到小合并，确保排序
}
return result;
}
int main(){
int n;
cin>>n;
for(int i=0;i<n;++i)
cin>>a[i];
printf("%lld",MergeSort(a,0,n-1,b));
return 0;
}
