#include <bits/stdc++.h>

using namespace std;

#define MAXN 50050

int N;
int A[2 * MAXN];
int P[MAXN];
int aib[2 * MAXN];

int query(int pos) {
  int ret = 0;
  while (pos > 0) {
    ret += aib[pos];
    pos -= pos & (-pos);
  }
  return ret;
}

int query(int a, int b) {
  return query(b) - query(a - 1);
}

void update(int pos, int val) {
  while (pos <= 2 * N) {
    aib[pos] += val;
    pos += pos & (-pos);
  }
}

int main() {
	// assert(freopen("cc.in", "r", stdin));
	// assert(freopen("cc.out", "w", stdout));
	cin.sync_with_stdio(false);

	cin >> N;
  for (int i = 1; i <= 2 * N; i++) {
    cin >> A[i];
  }

  long long ans = 0;
  for (int i = 1; i <= 2 * N; i++) {
    if (P[A[i]] == 0) {
      P[A[i]] = i;
      continue;
    }

    int prev = P[A[i]];

    int cross = query(prev, i);
    ans += cross;

    update(prev, -1);
    update(i, +1);
  }

  cout << ans << endl;

	return 0;
}