include [HTML_REMOVED]

using namespace std;
typedef long long ll;
const int N=100010;
int n,q[N],tmp[N];

ll merge_sort(int l,int r){
if(l>=r) return 0;
int mid=(l+r)/2;
ll res=merge_sort(l,mid)+merge_sort(mid+1,r);
int k=0,i=l,j=mid+1;
while(i<=mid && j<=r)
if(q[i]<=q[j]) tmp[k]=q[i];
else {
tmp[k]=q[j];
res+=mid-i+1;
}
while(i<=mid) tmp[k]=q[i];
while(j<=r) tmp[k]=q[j];
for(int i=l,j=0;i<=r;i,j)
q[i]=tmp[j];

return res;

}

int main ()
{
scanf(“%d”,&n);
for(int i=0;i<n;i++) scanf(“%d”,&q[i]);
cout << merge_sort(0,n-1) << endl;
return 0;
}