#include <iostream>
#include <vector>
#include <algorithm>
#define ll long long
#define vll vector<ll>
using namespace std;
ll count_swaps(vector<int> S)
{
ll n = S.size()/2;
vll arr(2 * n);
for (ll i = 0; i < 2 * n; i++) arr[i] = S[i];
/*
cout << "arr: " << endl;
for (ll i = 0; i < 2 * n; i++)
{
cout << arr[i] << " ";
}
*/
ll ans = 0;
for (ll i = 0; i < 2 * n; i += 2)
{
ll ind = -1;
for (ll j = i + 1; j < 2*n; j++)
{
if (arr[j] == -arr[i])
{
ind = j;
break;
}
}
//cout << "ind: " << ind << endl;
for (ll j = ind; j > i+1; j--)
{
swap(arr[j], arr[j - 1]);
ans++;
}
if (arr[i+1] < arr[i])
{
swap(arr[i], arr[i + 1]);
ans++;
}
}
/*
cout << "arr: " << endl;
for (ll i = 0; i < 2 * n; i++)
{
cout << arr[i] << " ";
}
cout << endl;
*/
//cout << ans << endl;
return ans;
}
/*
int main()
{
ll n;
cin >> n;
vector<int> arr(2 * n);
for (ll i = 0; i < 2 * n; i++) cin >> arr[i];
ll ans = count_swaps(arr);
cout << "ans: " << ans << endl;
}
*/
/*
2
2 1 -1 -2
*/
