#include<bits/stdc++.h>
#define ll long long int
#define FOR(i,N) for(i=0;i<N;i++)
#define FORe(i,N) for(i=1;i<=N;i++)
#define FORr(i,a,b) for(i=a;i<b;i++)
#define ii pair<ll,ll>
#define vi vector<ll>
#define vii vector<ii>
#define ff first
#define ppppppppp second
#define mp make_pair
#define pb push_back
using namespace std;
//#include "shoes.h"
/*
const ll MAXN = 1e5+5;
const ll INF = 1e17 + 9;
const ll MOD = 1e9 + 7;
const ll INT_BITS = 31;
const ll LOGN = 17;
*/
#define MAXN 200005
struct SegTree
{
ll st[4*MAXN];
void upd(ll node,ll ss,ll se,ll i)
{
if (i >se or i< ss)
return;
if (ss == se)
{
st[node] = 1;
return;
}
ll mid = (ss+se)/2;
upd(node*2+1,ss,mid,i);
upd(node*2+2,mid+1,se,i);
st[node] = st[node*2+1]+st[node*2+2];
}
ll quer(ll node, ll ss, ll se,ll l,ll r)
{
if (l>se or r<ss)
return 0;
if (l <= ss and r >=se)
return st[node];
ll mid = (ss+se)/2;
return quer(node*2+1,ss,mid,l,r)+quer(node*2+2,mid+1,se,l,r);
}
SegTree()
{
ll i;
FOR(i,4*MAXN)
st[i] = 0;
}
inline void update(ll i)
{
upd(0,0,MAXN,i);
}
inline ll query(ll l,ll r)
{
return quer(0,0,MAXN,l,r);
}
};
long long count_swaps(vector<int>s)
{
//cout<<"p\n";
ll N,i,j,l,r,ans = 0;
//cin>>N;
N = s.size();
SegTree S;
ll A[N],pr[N];
queue<ll> L[1 + N],R[N+1];
bool rem[N];
FOR(i,N)
{
A[i] = s[i];
//cout<<"entering for i = "<<i<<endl;
rem[i] = false;
if (A[i] < 0) // Left shoe
{
if (!R[-A[i]].empty())
{
r = R[-A[i]].front();
R[-A[i]].pop();
pr[r] = i;
pr[i] = r;
A[i] *= -1;
A[r] *= -1;
ans++;
}
else
L[-A[i]].push(i);
}
else if (A[i] > 0) // Right Shoe;
{
if (!L[A[i]].empty())
{
l = L[A[i]].front();
L[A[i]].pop();
pr[l] = i;
pr[i] = l;
}
else
R[A[i]].push(i);
}
}
/*
FOR(i,N)
cout<<A[i]<<" ";
cout<<endl;
FOR(i,N)
cout<<pr[i]<<" ";
cout<<endl;
*/
FOR(i,N)
{
if(A[i] < 0)
{
ans += pr[i]-i-1;
ans -= S.query(i,pr[i]);
/*for(j = i + 1;j<pr[i];j++)
if (rem[j])
ans--;*/
S.update(pr[i]);
rem[pr[i]] = true;
}
}
return ans;
}
/*
int main()
{
ll i,n;
cin>>n;
vector<int> s(2*n);
FOR(i,2*n)
cin>>s[i];
//cout<<"input taken\n";
i = count_swaps(s);
cout<<i<<endl;
return 0;
}*/
