include [HTML_REMOVED]
using namespace std;
const int N = 100010;
int a[N];
int temp[N];
long long find(int a[], int l, int r){
if(l >= r) return 0;
int mid = l + (r - l >> 1);
long long res = 0;
res += find(a, l, mid);
res += find(a, mid + 1, r);
int i = l, j = mid + 1, k = 0;
while(i <= mid && j <= r){
if(a[i] <= a[j]) temp[k++] = a[i++];
else
{
temp[k++] = a[j++];
res += mid - i + 1;
}
}
while(i <= mid) temp[k++] = a[i++];
while(j <= r) temp[k++] = a[j++];
for(i = l,k = 0;i <= r;i++)
a[i] = temp[k++];
return res;
}
int main(){
int n;
cin >> n;
for(int i = 0; i < n;i++){
cin >> a[i];
}
cout << find(a, 0 ,n - 1);
}