include[HTML_REMOVED]

const int N = 100000;
int q[N],temp[N];
long long int pair=0;
void merge_sort(int q[],int l,int r)
{
if(l>=r) return;
int mid=l+r>>1;
merge_sort(q,l,mid);
merge_sort(q,mid+1,r);

int k=0,i=l,j=mid+1;
while(i<=mid&&j<=r)
{
    if(q[i]<=q[j]) temp[k++]=q[i++];
    else
    {
     pair+=mid+1-i;    
     temp[k++]=q[j++];
    }
}
while(i<=mid) temp[k++]=q[i++];
while(j<=r) temp[k++]=q[j++];
for(int i=l,j=0;i<=r;i++,j++) q[i]=temp[j];

}
int main()
{
int n;
scanf(“%d”,&n);
for(int i=0;i<n;i++) scanf(“%d”,q+i);
merge_sort(q,0,n-1);
printf(“%lld”,pair);
return 0;
}