#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
const int N=1e5+5;
int n , m , c , w , k , t=1 , q=1 , x , y , z , l , r;
int fn[N];
void add(int i,int x){
if (i<N){
fn[i]+=x;
add(i+(i&-i),x);
}
}
int pr(int i){
if (i==0)return 0;
return fn[i]+pr(i-(i&-i));
}
ll count_swaps(vector<int>a)
{
int n=a.size()/2;
a.push_back(a[2*n-1]);
for (int i=2*n-1;i>0;i--){
a[i]=a[i-1];
}
map<int,queue<int>>d;
for (int i=1;i<=2*n;i++){
d[a[i]].push(i);
}
ll c=0;
vector<pair<int,int>>k;
for (int i=1;i<=2*n;i++){
if (d[a[i]].size() and d[a[i]].front()==i){
k.push_back({d[-a[i]].front()-i,i});
d[a[i]].pop();
d[-a[i]].pop();
}
}
sort(k.begin(),k.end());
for (int i=0;i<n;i++){
c+=k[i].fi;
if (a[k[i].se]<0)c--;
c-=pr(k[i].fi+k[i].se)-pr(k[i].se);
add(k[i].se,1);
add(k[i].se+k[i].fi,-1);
}
return c;
}
// signed main() {
// #ifndef ONLINE_JUDGE
// freopen("input.txt","r",stdin);
// freopen("output.txt","w",stdout);
// #endif
// cin >> n;
// // assert(1 == scanf("%d", &n));
// vector<int> S(2 * n);
// for (int i = 0; i < 2 * n; i++)
// assert(1 == scanf("%d", &S[i]));
// fclose(stdin);
// ll result = count_swaps(S);
// printf("%lld\n", result);
// fclose(stdout);
// return 0;
// }
