#include "shoes.h"
#include <bits/stdc++.h>
#define lll long long
#define emb emplace_back
#define em emplace
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define pii pair <int, int>
using namespace std;
const int N = 2e5 + 5;
struct {
int seg[4 * N];
void update(int l, int r, int i, int idx, int val){
if (l == r) return seg[i] = val, void();
int mid = (l + r) / 2;
if (idx <= mid) update(l, mid, 2 * i, idx, val);
else update(mid + 1, r, 2 * i + 1, idx, val);
seg[i] = seg[2 * i] + seg[2 * i + 1];
}
int query(int l, int r, int i, int ll, int rr){
if (l >= ll && r <= rr) return seg[i];
if (r < ll || l > rr) return 0;
int mid = (l + r) / 2;
return query(l, mid, 2 * i, ll, rr) + query(mid + 1, r, 2 * i + 1, ll, rr);
}
int search(int l, int r, int i, int k){
if (l == r) return l;
int mid = (l + r) / 2;
if (seg[2 * i] >= k) return search(l, mid, 2 * i, k);
else return search(mid + 1, r, 2 * i + 1, k - seg[2 * i]);
}
} seg;
lll count_swaps(vector<int> a) {
memset(seg.seg, 0, sizeof seg.seg);
int n = a.size()/2;
reverse(all(a)); a.emb(0); reverse(all(a));
map <int, set <int>> mp;
for (int i = 1; i <= 2*n; i++) {
mp[a[i]].em(i);
seg.update(1, 2*n, 1, i, 1);
}
// for (int i = 1; i <= 2 * n; i++) cout << seg.query(1, 2*n, 1, i, i) << " "; cout << "\n";
lll ans = 0;
for (int i = 1; i <= 2*n; i++) {
if (i % 2 == 0) continue;
int idx = i;
int val = a[idx];
int nxt = *mp[val * -1].begin();
mp[val].erase(idx);
mp[val * -1].erase(nxt);
ans += seg.query(1, 2*n, 1, idx, nxt) - 1 - (val < 0);
// cout << i << ": " << val << "\n";
// cout << "[" << idx << ", " << nxt << "]\n";
// cout << "ANS FOR " << i << " : " << seg.query(1, 2*n, 1, idx, nxt) - 1 - (val < 0) << "\n";
seg.update(1, 2*n, 1, idx, 0);
seg.update(1, 2*n, 1, nxt, 0);
// for (int j = 1; j <= 2*n; j++) {
// cout << seg.query(1, 2*n, 1, i, i) << " ";
// }
// cout << "\n";
// cout << "-------------\n";
}
return ans;
}
/*
OMG
OBSERVE ORK LAEW
*/
