#include <iostream>
#include <vector>
#include <bitset>

using namespace std;
typedef long long int64;

const int kMaxN = 1e5+10;
bitset<50000> b[kMaxN];
int first[kMaxN], v[kMaxN];

int main() {
	int n;
	cin >> n;

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

	int64 rez = 0;

	for (int i = 1; i <= 2*n; ++i) {
		b[i] = b[i-1];
		b[i].flip(v[i]);

		if (first[v[i]] == 0) {
			first[v[i]] = i;
		} else {
			auto ans = b[i] ^ b[first[v[i]] - 1];
			rez += ans.count();
		}
	}

	cout << rez/2 << "\n";
}