#include <iostream>
#include <map>
#include <set>
#include <algorithm>
#include <vector>
using namespace std;

int n;

int main()
{
	ios::sync_with_stdio(false);

	cin >> n;

	vector<int> a = vector<int>(n + 1, 0);
	vector<int> b = vector<int>(n + 1, 0);
	vector<int> v = vector<int>(2*n + 1, 0);


	for (int i = 1; i <= 2*n; i++) {
		int c;
		cin >> c;
		v[i] = c;
		if (a[c] == 0) {
			a[c] = i;
		}
		else {
			b[c] = i;
		}

		
	}
	int sum = 0;
	
	int ct = 0;
	for (int i = 1; i <= n; i++) {
		int mini = min(a[i], b[i]), maxi=max(a[i],b[i]);

		map<int, int> m;

		for (int j = mini+1; j < maxi; j++) {
			if (m.find(v[j]) != m.end()) {
				sum--;
			}
			else {
				sum++;
				m[v[j]]=1;
			}
		}

	}

	cout << sum/2;

    return 0;
}