//  ↘ ⬇ ⬇ ⬇ ⬇ ⬇ ↙
//  ➡ @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
struct segtree {
    int sz;
    vector<int> tree;
    void init(int n) {
        sz = 1;
        while (sz < n) {
            sz *= 2;
        }
        tree.assign(sz * 2, {});
        for (int i = 0; i < n; ++i) {
            tree[sz + i] = 1;
        }
        for (int i = sz-1; i > 0; --i) {
            tree[i] = tree[i * 2] + tree[i * 2 + 1];
        }
    }
    int get(int l, int r) {
        l += sz;
        r += sz;
        int res = 0;
        while (l <= r) {
            if (l % 2) {
                res += tree[l];l++;
            }
            if (r % 2 == 0) {
                res += tree[r];
                r--;
            }
            l /= 2;r /= 2;
        }
        return res;
    }
    void ch(int v) {
        v += sz;
        tree[v] = 0;
        while (v != 1) {
            v /= 2;
            tree[v] = tree[v * 2] + tree[v * 2 + 1];
        }
    }
};
long long count_swaps(vector<int> s) {
    long long res = 0;
    map<int, vector<int>> poses;
    for (int i = 0; i < s.size(); ++i) {
        poses[s[i]].push_back(i);
    }
    segtree sg;
    sg.init(s.size());
    for (int ind = s.size() - 1; ind >= 0; --ind) {
        if (sg.get(ind, ind)) {
            int vl = s[ind];
            poses[vl].pop_back();
            sg.ch(ind);
            if (vl < 0)
                res++;
            int beb = poses[-vl].back();
            poses[-vl].pop_back();
            sg.ch(beb);
            res += sg.get(beb, ind);
        }
    }
    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