#ifndef KURUMI
#include "shoes.h"
#endif
#include <bits/stdc++.h>
using namespace std;
#ifdef KURUMI
#include "algo/debug.h"
#endif
#define endl '\n'
#define fi first
#define se second
#define sz(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define filter(v) v.resize(unique(all(v)) - v.begin())
#define dbg(x) "[" #x << " = " << x << "]"
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template<typename T1, typename T2> T2 rand(T1 l, T2 r) {
return uniform_int_distribution<T2>(l, r)(rng);
}
template<typename T1, typename T2> T2 wrand(T1 l, T2 r, int seed) {
if(seed == 0) return rand(l, r);
else return (seed > 0 ? max(rand(l, r), wrand(l, r, seed - 1)) : min(rand(l, r), wrand(l, r, seed + 1)));
}
template<typename S, typename T> bool maximize(S &a, T b) {
if(a < b) {
a = b;
return true;
}else return false;
}
template<typename S, typename T> bool minimize(S &a, T b) {
if(a > b) {
a = b;
return true;
}else return false;
}
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, int> pli;
typedef pair<ll, ll> pll;
typedef tuple<int, int, int> tp3;
const int N = 2e5 + 3;
const ll INF = 1e18 + 3;
int n;
int a[N];
namespace subtask_1 {
bool approve() {
return n == 1;
}
ll execute() {
return (a[1] > a[2]);
}
}
namespace subtask_2 {
bool approve() {
return n <= 8;
}
const int N = 12;
ll answer = INF;
int order[N];
deque<int> pos[N], tmp[N];
int calc() {
int tot = 0;
for(int i = 1; i <= 2 * n; i++) {
for(int j = 1; j < i; j++) {
tot += (order[j] > order[i]);
}
}
return tot;
}
ll execute() {
vector<int> lab;
for(int i = 1; i <= 2 * n; i++) {
if(a[i] > 0) pos[a[i]].push_back(i);
else lab.push_back(i);
}
do {
for(int i = 1; i <= n; i++) tmp[i] = pos[i];
for(int i = 1; i <= 2 * n; i += 2) order[i] = lab[(i - 1) / 2];
for(int i = 2; i <= 2 * n; i += 2) {
order[i] = tmp[-a[lab[i / 2 - 1]]].front();
tmp[-a[lab[i / 2 - 1]]].pop_front();
}
minimize(answer, calc());
}while(next_permutation(all(lab)));
return answer;
}
}
namespace subtask_6 {
bool approve() {
return true;
}
struct FenwickTree {
vector<int> tr;
FenwickTree (int n) : tr(n + 3) {}
void update(int p, int v) {
for(; p > 0; p -= p & -p)
tr[p] += v;
}
int get(int p) {
int tot = 0;
for(; p < sz(tr); p += p & -p) tot += tr[p];
return tot;
}
};
int last[N];
bool pushed[N];
deque<int> big[N], small[N];
ll execute() {
vector<int> order;
// optimal because it does not interfere with any other swap
for(int i = 2 * n; i >= 1; i--) {
if(a[i] < 0) {
a[i] = -a[i];
if(!big[a[i]].empty()) {
// cout << i << " " << big[a[i]].front() << endl;
order.push_back(big[a[i]].front());
order.push_back(i);
big[a[i]].pop_front();
}else small[a[i]].push_back(i);
}else {
if(!small[a[i]].empty()) {
// cout << i << " " << small[a[i]].front() << endl;
order.push_back(i);
order.push_back(small[a[i]].front());
small[a[i]].pop_front();
}else big[a[i]].push_back(i);
}
}
ll answer = 0;
FenwickTree ft(2 * n);
reverse(all(order));
for(int p : order) {
answer += ft.get(p);
ft.update(p, 1);
}
return answer;
}
}
ll count_swaps(vector<int> s) {
n = sz(s) / 2;
for(int i = 1; i <= 2 * n; i++) {
a[i] = s[i - 1];
}
if(subtask_1::approve()) return subtask_1::execute();
if(subtask_2::approve()) return subtask_2::execute();
if(subtask_6::approve()) return subtask_6::execute();
return -1;
}
#ifdef KURUMI
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
#define task "Deeto"
if(fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
int n; cin >> n;
vector<int> s(2 * n);
for(int i = 0; i < 2 * n; i++) cin >> s[i];
cout << count_swaps(s) << endl;
cerr << "Saa, watashtachi no deeto hajimemashou" << endl;
cerr << "Atarashii kiseki wo koko kara hajimeru shining place nee mou ichido kimi to..." << endl;
return 0;
}
#endif
