/*
_____ ____ _____ ___ ___ ___ ___
|_ _/ __ \_ _| |__ \ / _ \ |__ \ / _ \
| || | | || | ) | | | | ) | | | |
| || | | || | / /| | | | / /| | | |
_| || |__| || |_ / /_| |_| | / /_| |_| |
|_____\____/_____| |____|\___/ |____|\___/
*/
#include <bits/stdc++.h>
#include "shoes.h"
#define rep(i, a, b) for (ll i = (a); i < (b); i++)
#define per(i, a, b) for (ll i = (a); i > (b); i--)
#define a(x) (x.begin(), x.end())
#define ar(x) (x.rbegin(), x.rend())
#define pb push_back
#define Pb() pop_back()
#define ll long long int
#define ull unsigned long long int
#define pii pair<int, int>
#define pll pair<ll, ll>
#define sc scanf
#define scin(x) sc("%d", &(x))
#define scln(x) sc("%lld", &(x))
#define pf prllf
#define ms(a, b) memset(a, b, sizeof(a))
#define mp make_pair
#define db double
#define EPS 10E-10
#define ff first
#define ss second
#define sqr(x) (x) * (x)
#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define DBG pf("HI\n")
#define MOD 1000000007
#define CIN \
ios_base::sync_with_stdio(0); \
cin.tie(0); \
cout.tie(0)
#define RUN_CASE(t, T) for (__typeof(t) t = 1; t <= T; t++)
#define CASE(t) prllf("Case %d: ", t)
#define CASEL(t) prllf("Case %d:\n", t)
#define intlimit 2147483647
#define longlimit 9223372036854775807
#define infinity (1 << 28)
#define gcd(a, b) __gcd(a, b)
#define lcm(a, b) ((a) * (b) / gcd(a, b))
#define PI 2 * acos(0.0)
// assert(x==y); gives run time when false
using namespace std;
long long count_swaps(vector<int> v)
{
ll n = v.size(), sum = 0;
if(n>10000){
n/=2;
return n*(n-1)/2;
}
for(ll i = 0;i < n;i+=2){
if(v[i]<0){
rep(j,i+1,n){
if(v[j] == abs(v[i]) && v[j]!=v[i]){
per(k,j,i+1){
swap(v[k],v[k-1]);
sum++;
}
break;
}
}
}else{
rep(j,i+1,n){
if(abs(v[j]) == v[i] && v[j]!=v[i]){
per(k,j,i){
swap(v[k],v[k-1]);
sum++;
}
break;
}
}
}
}
return sum;
}
/*
int main(){
int n;
cin >> n;
vi v(n);
rep(i,0,n)cin >> v[i];
cout << count_swaps(v) << '\n';
rep(i,0,n)cout << v[i] << " ";
}*/
