#include <bits/stdc++.h>
using namespace std;
#define lazy ios::sync_with_stdio(false); cin.tie(nullptr);
const int OFFSET = 100000;
vector<int> tree;
void build(int node, int l, int r) {
if (l == r) {
tree[node] = 1;
return;
}
int mid = l + (r - l) / 2;
build(2 * node, l, mid);
build(2 * node + 1, mid + 1, r);
tree[node] = tree[2 * node] + tree[2 * node + 1];
}
void update(int node, int l, int r, int idx, int val) {
if (l == r) {
tree[node] = val;
return;
}
int mid = l + (r - l) / 2;
if (idx <= mid) update(2 * node, l, mid, idx, val);
else update(2 * node + 1, mid + 1, r, idx, val);
tree[node] = tree[2 * node] + tree[2 * node + 1];
}
int query(int node, int l, int r, int ql, int qr) {
if (ql > r || qr < l) return 0;
if (ql <= l && r <= qr) return tree[node];
int mid = l + (r - l) / 2;
return query(2 * node, l, mid, ql, qr) + query(2 * node + 1, mid + 1, r, ql, qr);
}
long long count_swaps(vector<int> S) {
int n = S.size() / 2;
tree.assign(8 * n, 0);
build(1, 0, 2 * n - 1);
vector<queue<int>> pos(200005);
for (int i = 0; i < 2 * n; i++) {
pos[S[i] + OFFSET].push(i);
}
vector<bool> visited(2 * n, false);
long long total_swaps = 0;
for (int i = 0; i < 2 * n; i++) {
if (visited[i]) continue;
visited[i] = true;
pos[S[i] + OFFSET].pop();
int target_shoe = -S[i];
int j = pos[target_shoe + OFFSET].front();
pos[target_shoe + OFFSET].pop();
visited[j] = true;
int unvisited_between = 0;
if (i + 1 <= j - 1) {
unvisited_between = query(1, 0, 2 * n - 1, i + 1, j - 1);
}
if (S[i] < 0) {
total_swaps += unvisited_between;
} else {
total_swaps += unvisited_between + 1;
}
update(1, 0, 2 * n - 1, i, 0);
update(1, 0, 2 * n - 1, j, 0);
}
return total_swaps;
}
