#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define ss second
#define ff first
using namespace std;
ll df[1234567],ans;
vector<ll> vv[1234567];
struct segtree{
ll n;
vector<ll>d;
segtree(ll n){
d.resize(4*n);
build(1,1,n);
}
void build(ll v, ll l, ll r){
if(l == r){
d[v] = 1;
return;
}
ll m = (l+r)/2;
build(v*2,l,m);
build(v*2+1,m+1,r);
d[v] = d[v*2]+d[v*2+1];
}
void update(ll v,ll l, ll r, ll pos, ll val){
if(pos < l or pos > r)return;
if(l == r){
d[v] = val;
return;
}
ll m = (l+r)/2;
update(v*2,l,m,pos,val);
update(v*2+1,m+1,r,pos,val);
d[v] = d[v*2]+d[v*2+1];
}
ll query(ll v, ll l, ll r, ll L, ll R){
if(R<L||R<l||r<L) return 0ll;
if(L<=l&&r<=R) return d[v];
ll m = (l+r)/2;
return query(v*2,l,m,L,R) + query(v*2+1,m+1,r,L,R);
}
};
int count_swaps(vector<int> a){
int n = a.size() / 2;
map<int, vector<int>> w;
for(int i = 0; i < a.size(); ++i){
w[a[i]].push_back(i + 1);
}
vector<pair<int,int>> v;
int cnt = 0;
for(auto& [key, vec] : w){
if(key < 0) continue;
auto& left = w[-key];
auto& right = w[key];
for(int i = 0; i < left.size(); ++i){
if(left[i] < right[i]){
v.push_back({left[i] + 1, right[i] - 1});
} else {
v.push_back({right[i] + 1, left[i] - 1});
cnt++;
}
}
}
sort(v.begin(), v.end());
segtree yo(2 * n);
for(auto [l, r] : v){
cnt += yo.query(1, 1, 2*n, l, r);
yo.update(1, 1, 2*n, r + 1, 0);
}
return cnt;
}
