#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mxN=101010;
queue <int> que[2*mxN];
bool Chk[2*mxN];
int seg[8*mxN];
void init(int idx, int s, int e)
{
seg[idx]=e-s+1;
if(s!=e)
{
int mid=(s+e)/2;
init(2*idx, s, mid);
init(2*idx+1, mid+1, e);
}
}
int sum(int idx, int s, int e, int str, int fin)
{
if(s>fin || str>e) return 0;
if(str<=s && e<=fin) return seg[idx];
int mid=(s+e)/2;
return sum(2*idx, s, mid, str, fin)+sum(2*idx+1, mid+1, e, str, fin);
}
void upd(int idx, int s, int e, int pos)
{
if(pos<s || pos>e) return;
seg[idx]--;
if(s!=e)
{
int mid=(s+e)/2;
upd(2*idx, s, mid, pos);
upd(2*idx+1, mid+1, e, pos);
}
}
long long count_swaps(vector<int> s)
{
ll ans=0;
int N=s.size()/2;
for(int i=0;i<2*N;i++)
{
que[s[i]+N].push(i);
}
init(1, 0, 2*N-1);
for(int i=0;i<2*N;i++)
{
if(Chk[i]) continue;
int left=N+s[i];
int right=N-s[i];
int nxt=que[right].front();
que[right].pop();
que[left].pop();
ans+=sum(1, 0, 2*N-1, i, nxt)-2;
if(s[i]>0) ans++;
upd(1, 0, 2*N-1, nxt);
upd(1, 0, 2*N-1, i);
Chk[i]=true;
Chk[nxt]=true;
}
return ans;
}
