#include <bits/stdc++.h>
typedef long long ll;
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
using namespace std;
typedef pair<int, int> pi;
const int MAXN = 2e5 + 1;
int n;
int bit[MAXN];
void upd(int i, int v)
{
for (; i <= 2 * n; i += i & -i)
bit[i] += v;
}
ll sum(int i)
{
ll res = 0;
for (; i > 0; i -= i & -i)
res += bit[i];
return res;
}
ll count_swaps(vector<int> S)
{
ll ans = 0;
n = sz(S) / 2;
vector<pi> swaps;
vector<pi> idx[n + 1];
for (int i = 0; i < 2 * n; i++)
idx[abs(S[i])].push_back({S[i], i + 1});
for (int i = 1; i <= n; i++)
{
sort(all(idx[i]));
// for (auto x : idx[i])
// cout << x.first << " " << x.second << endl;
for (int j = 0; j < sz(idx[i]) / 2; j++)
{
int l = idx[i][j].second;
int r = idx[i][j + sz(idx[i]) / 2].second;
if (l > r)
{
swap(l, r);
ans++;
}
swaps.push_back({l, r});
}
}
sort(all(swaps));
// for (auto x : swaps)
// cout << x.first << " " << x.second << endl;
for (int i = 1; i <= 2 * n; i++)
upd(i, 1);
// cout << "ans = " << ans << endl;
for (auto s : swaps)
{
// ans += sum(s.second - 1) - sum(s.first);
ans += sum(s.second - 1) - sum(s.first);
upd(s.first, -1);
// cout << "s = " << s.first << " " << s.second << endl;
upd(s.second, -1);
}
return ans;
}
// int main()
// {
// int t;
// cin >> t;
// vector<int> S(t * 2);
// for (auto &x : S)
// cin >> x;
// // for (auto x : S)
// // cout << x << " ";
// // cout << endl;
// cout << count_swaps(S) << endl;
// return 0;
// }
