#include <bits/stdc++.h>
#include "shoes.h"
using namespace std;
#define int long long
#define vo vector
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
typedef vector<int> vi;
typedef pair<int, int> pii;
typedef long long ll;
#define rep(i, a, b) for(int i=(a); i<(b); i++)
#define repd(i, a, b) for(int i=(b-1); i>=(a); i--)
#define pr(x) cerr << #x << " = " << x << endl;
int const inf = 1e18, mxn = 2e5+4;
int n;
struct segtree{
vi seg;
int n;
segtree(int _n): n(_n), seg(_n*4, 0){}
void upd(int v, int l, int r, int pos, int add){
if(l==r) {seg[v]+=add; return;}
int mid = (l+r)/2;
if(pos<=mid) upd(v*2+1, l, mid, pos, add);
else upd(v*2+2, mid+1, r, pos, add);
seg[v] = seg[v*2+1] + seg[v*2+2];
}
int qry(int v, int l, int r, int ql, int qr){
if(ql<=l && r<=qr) return seg[v];
if(ql>r || l>qr) return 0;
int mid = (l+r)/2;
return qry(2*v+1, l, mid, ql, qr) + qry(2*v+2, mid+1, r, ql, qr);
}
};
int count_swaps(vector<signed> inp){
n = inp.size()/2;
vi fixed(2*n);
map<int, vi> occ;
segtree seg(2*n);
repd(i, 0, 2*n){
seg.upd(0, 0, seg.n-1, i, 1);
occ[inp[i]].pb(i);
}
int i = 0, ans = 0;
while(i<2*n){
if(fixed[i]) {i++; continue;}
int x = inp[i];
vi &tmp = occ[-x];
int nex = tmp.back(); tmp.pop_back(); occ[x].pop_back();
fixed[i] = fixed[nex] = 1;
seg.upd(0, 0, seg.n-1, i, -1); seg.upd(0, 0, seg.n-1, nex, -1);
if(x<0) ans += seg.qry(0, 0, seg.n-1, i, nex);
else ans += seg.qry(0, 0, seg.n-1, i, nex) + 1;
i++;
}
return ans;
}
/*
3
-1 -1 -3 1 1 3
svar: 2+2+1=5
*/
