#include <bits/stdc++.h>
using namespace std;
const int N = 100;
int bit[N + 10];
int sum(int i) {
  int s = 0;
  while (i > 0) {
    s += bit[i];
    i -= i & -i;
  }
  return s;
}
void add(int i, int x) {
  while (i <= N) {
    bit[i] += x;
    i += i & -i;
  }
}
vector<int> compress(vector<int> v) {
  map<int, int> mp;
  for (int i = 0; i < v.size(); i++) mp[i] = 0;
  int id = 1;
  for (map<int, int>::iterator it = mp.begin(); it != mp.end(); it++) {
    it->second = id++;
  }
  for (int i = 0; i < v.size(); i++) v[i] = mp[v[i]];
  return v;
}
int main() {
  int n;
  while (cin >> n && n) {
    memset(bit, 0, sizeof(bit));
    vector<int> v(n);
    for (int i = 0; i < n; i++) cin >> v[i];
    v = compress(v);
    int ans = 0;
    for (int i = n - 1; i >= 0; i--) {
      ans += sum(v[i] - 1);
      add(v[i], 1);
    }
    cout << ans << endl;
  }
  return 0;
}
