#include "shoes.h"//
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
#define ft first
#define sd second
using namespace std;
using namespace __gnu_pbds;
typedef pair<int, int> pii;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
const int MAXN = 100 * 1000 + 23;
map<int, deque<int>> v;
ordered_set t;
vector<pii> vec;
long long count_swaps(vector<int> s) {
int n = s.size() / 2, cnt = 0, a[MAXN << 1];
long long ans = 0;
for (int i = 0; i < (n << 1); i++) {
v[s[i]].push_back(i);
if (!v[-s[i]].empty()) {
if (s[i] > 0) vec.push_back({v[-s[i]].front(), i});
else vec.push_back({i, v[-s[i]].front()});
v[s[i]].pop_back();
v[-s[i]].pop_front();
}
}
// for (auto i : vec) cout << i.ft << ' ' << i.sd << endl;
sort(vec.begin(), vec.end(), [](pii x, pii y) { return x.ft + x.sd < y.ft + y.sd; });
for (auto i : vec) {
// cout << i.ft << ' ' << i.sd << endl;
a[i.ft] = cnt++;
a[i.sd] = cnt++;
}
for (int i = 0; i < (n << 1); i++) {
// cout << a[i] << ' ';
ans += t.size() - t.order_of_key(a[i]);
t.insert(a[i]);
}
//cout << endl;
return ans;
}
//int main() {cout << count_swaps({2, 1, -1, -2});}//
