#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 69;
int f[N];
int m;
void add(int x, int v){
for (int i = x; i <= m; i += i & (-i)) f[i] += v;
}
int sum(int x){
int ret = 0;
for (int i = x; i; i -= i & (-i)) ret += f[i];
return ret;
}
long long count_swaps(vector<int> s) {
long long ans = 0;
int n = s.size() / 2;
m = 2 * n;
vector <int> match(m + 1, -1);
deque <int> store[n + 1];
for (int i = 0; i < m; i++){
int x = abs(s[i]);
int sgn = s[i] / x;
if (sgn == 1){
if (store[x].size() > 0 && store[x][0] < 0){
match[-store[x][0]] = i + 1;
match[i + 1] = -store[x][0];
store[x].pop_front();
} else {
store[x].push_back(i + 1);
}
} else {
if (store[x].size() > 0 && store[x][0] > 0){
match[store[x][0]] = i + 1;
match[i + 1] = store[x][0];
store[x].pop_front();
} else {
store[x].push_back(-i - 1);
}
}
}
for (int i = 1; i <= 2 * n; i++) add(i, 1);
for (int i = 1; i <= 2 * n; i++){
if (match[i] < i) continue;
int holy;
holy = sum(match[i] - 1) - sum(i);
// cout << holy << " ";
if (s[match[i] - 1] < 0) holy++;
// cout << holy << "\n";
ans += holy;
add(match[i], -1);
}
return ans;
}
// int main(){
// int n; cin >> n;
// vector <int> a(n);
// for (auto &x : a) cin >> x;
// cout << count_swaps(a) << "\n";
// return 0;
// }
