#include "shoes.h"
#include <bits/stdc++.h>
#define sz(x) (int)(x).size()
#define forn(i, x) for (int i = 0; i < (int)x; i++)
#define pb push_back
#define rforn(i, x) for (int i = (int)x - 1; i >= 0; i--)
#define pii pair<int, int>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define ff first
#define ss second
using namespace std;
template<class T>
void print(T a) {
for (auto x : a)
cout << x << ' ';
cout << endl;
}
long long count_swaps(vector<int> S) {
vector<int> a = S;
int n = sz(a);
map<int, int> prev;
map<int, int> neg, pos;
long long ans = 0;
forn (i, 2 * n) {
int val = a[i];
int val0 = abs(val);
if (val < 0)
neg[val0]++;
else
pos[val0]++;
if (neg[val0] > 0 && pos[val0] > 0) {
neg[val0]--;
pos[val0]--;
ans += i - prev[-val];
if (val > 0)
ans--;
} else {
prev[val] = i;
}
}
return ans;
}
