include[HTML_REMOVED]
typedef long long LL;
using namespace std;
const int N = 1e6+10;
int q[N],tmp[N];
LL merge_sort( int l , int r)
{
if(l >= r) return 0;
int mid = l + r >> 1;
LL ans = 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++];
ans += mid - i + 1;
}
}
while(i <= mid) tmp[k++] = q[i++];
while(j <= r) tmp[k++] = q[j++];
for(int i = l, k = 0; i <= r ; i++, k++) q[i] = tmp[k];
return ans;
}
int main()
{
int n;
scanf(“%d”,&n);
for(int i = 0; i < n; i++) scanf("%d",&q[i]);
cout << merge_sort( 0 , n - 1) <<endl;
// for(int i = 0; i < n; i++) printf("%d ",q[i]);
return 0;
}