//  ↘ ⬇ ⬇ ⬇ ⬇ ⬇ ↙
//  ➡ @roadfromroi ⬅
//  ↗ ⬆ ⬆ ⬆ ⬆ ⬆ ↖
#include <iostream>
#include "vector"
#include "algorithm"
#include "numeric"
#include "climits"
#include "iomanip"
#include "bitset"
#include "cmath"
#include "map"
#include "deque"
#include "array"
#include "set"
#include "shoes.h"
#define all(x) x.begin(), x.end()
using namespace std;
//#define LOCAL 1
long long count_swaps(vector<int> s) {
    int res = 0;
    while (!s.empty()) {
        int i = s.size() - 1;
        for (; i >= 0; --i) {
            if (s[i] > 0)
                break;
        }
        while (i + 1 != s.size()) {
            res++;
            swap(s[i], s[i + 1]);
            i++;
        }
        int k = -s.back();
        for (; i >= 0; --i) {
            if (s[i] == k)
                break;
        }
        while (i + 2 != s.size()) {
            res++;
            swap(s[i], s[i + 1]);
            i++;
        }
        s.pop_back();
        s.pop_back();
    }
    return res;
}
#ifdef LOCAL
    int main() {
        int n;
        assert(1 == scanf("%d", &n));
        vector<int> S(2 * n);
        for (int i = 0; i < 2 * n; i++)
            assert(1 == scanf("%d", &S[i]));
        fclose(stdin);

        long long result = count_swaps(S);

        printf("%lld\n", result);
        fclose(stdout);
        return 0;
    }
#endif