#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
typedef long long ll;
typedef double db;
typedef vector<long long> vl;
typedef pair<long long , long long > pl;
const int N=1e6+1;
#define po pop_back
#define pb push_back
#define mk make_pair
#define lw lower_bound
#define up upper_bound
#define ff first
#define ss second
#define boost ios_base::sync_with_stdio(); cin.tie(0); cout.tie(0);
#define MOD 1000000007
#define MAX 1e18
#define MIN -1e18
#define rep(i,a,b) for(ll i=a;i<=b;i++)
#define per(i,a,b) for(ll i=b;i>=a;i--)
#define con continue
#define freopen freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define PI 3.14159265358979323846264338327950288419716939937510582097494459230781640628
// typedef tree<ll , null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
// template< typename T>
// using indexed_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
ll sz,n,m,ans,mid,mn,mx,cnt,T,sum,h1,h2,e[1234567],b[1234567],c[1234567],d[1<<20],k,i,j,l,r,h,a[1234567],w,x,y,z;
bool used[1234567];
vector<ll> v[1234567];
ll dx[4]={-1,1,0,0},dy[4]={0,0,-1,1},c1[123][123];
bool check(ll x){
if(x>=0)return 0;
else return 1;
}
int count_swaps(vector<int> vec){
ll res=0;
if(vec.size()<=2000){
for(ll i=0;i<vec.size()-1;i++){
ll tmp=-1;
ll j=i+1;
while(tmp == -1){
if(vec[j] == -vec[i]){
tmp = j;
}
j++;
}
if(check(vec[i])){
res += (tmp-i-1);
}
else{
res += (tmp-i);
}
vec.erase(vec.begin() + tmp);
}
return res;}
set<ll> st;
for(auto x:vec) st.insert(x);
if(st.size()==2){
vl v;
for(ll i=0;i<vec.size();i++){
if(vec[i]<0)v.pb(i);
}
ll now=0,ans=0;
for(ll i=0;i<vec.size();i++){
if(i%2==0){
ans += abs(v[now]-i);
now++;
}
}
return ans;
}
res = vec.size()/2;
return res*(res-1)/2;
}
