// Source: https://usaco.guide/general/io
#include <bits/stdc++.h>
#define ll long long
#define ff first
#define ss second
#define ln "\n"
const ll INF = 2e18;
const ll MOD = 1e9+7;
using namespace std;
struct Fenwick{
vector<ll> t;
ll n;
Fenwick(ll sz){
n = sz;
t.resize(n+1, 0);
}
void update(ll i, ll ch){
for (; i<=n; i+=(-i&i)) t[i]+=ch;
}
ll get(ll i){
ll sum = 0;
for (; i; i-=(-i&i)) sum+=t[i];
return sum;
}
};
long long count_swaps(vector<int> S){
ll n = S.size()/2;
Fenwick tr(2*n+1);
for (ll i=0; i<2*n; i++){
tr.update(i+1, 1);
}
unordered_map<ll, queue<ll>> pt;
vector<ll> elp(2*n, -1);
for (ll i=0; i<2*n; i++){
if (pt[-S[i]].empty()) {
pt[S[i]].push(i);
}else{
ll front = pt[-S[i]].front();
pt[-S[i]].pop();
elp[front]=i;
}
}
ll ans = 0;
for (ll i=0; i<2*n; i++){
if (elp[i]==-1) continue;
ll dif = tr.get(elp[i]+1)-tr.get(i+1)-1;
if (S[i]>0){
dif++;
}
ans+=dif;
tr.update(elp[i]+1, -1);
tr.update(i+1, -1);
}
return ans;
}
