#include <bits/stdc++.h>
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
using namespace std;
#include "shoes.h"
const int N = 2e5 + 5;
int bit[N];
void upd(int pos, int val) {
while(pos < N) {
bit[pos] += val;
pos += pos & -pos;
}
}
int get(int pos) {
int ret = 0;
while(pos) {
ret += bit[pos];
pos -= pos & -pos;
}
return ret;
}
bool marked[N];
int arr[N];
vector<int> occ[2 * N];
long long count_swaps(std::vector<int> s) {
int n = (int)s.size() / 2;
int m = 2 * n;
long long ans = 0;
int pos = 1;
for(int i = 1; i <= m; i++) {
arr[i] = s[i - 1];
}
for(int i = m; i >= 1; i--) {
occ[arr[i] + m].push_back(i);
}
for(int _ = 0; _ < n; _++) {
while(marked[pos]) {
pos += 1;
}
int num = arr[pos];
int target = -num;
int where = occ[target + m].back();
marked[pos] = true;
marked[where] = true;
occ[target + m].pop_back();
occ[num + m].pop_back();
int cur_pos = where + (get(m - 1) - get(where));
ans += cur_pos - (2 * _ + 2);
if(num > 0) ans += 1;
upd(where, 1);
}
return ans;
}
//int main() {
// ios_base::sync_with_stdio(false);
// cin.tie(0), cout.tie(0);
//
// file("A") else file("task");
//
// return 0;
//}
