#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
const long long int MOD = 1e9 + 7;
const long long int INF = 1000000000;
const long long int MAX_N = 2e5 + 2;
void solve() {
  int n;
  cin >> n;
  vector<int> v(2 * n);
  for (int i = 0; i < (2 * n); ++i) cin >> v[i];
  int cnt = 0;
  for (int i = 0; i < (2 * n) - 1; ++i) {
    if (v[i] != v[i + 1]) {
      for (int j = i + 1; j < (2 * n); ++j) {
        if (v[j] == v[i]) {
          while (j > i + 1) {
            swap(v[j], v[j - 1]);
            j--;
            cnt++;
          }
          break;
        }
      }
    }
    ++i;
  }
  cout << cnt;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  solve();
}
