# include <bits/stdc++.h>
# pragma GCC optimize("Ofast")
# define ll long long
# define fi first
# define se second
# define pb push_back
# define pf push_front
# define For(i, a, b) for( ll i = a; i < b; i++ )
# define in insert
# define all(a) a.begin(),a.end()
# define pi pair < ll, ll >
# define readfile(file) freopen ( (file + ".in").c_str(), "r", stdin)
# define writefile(file) freopen ( (file + ".out").c_str(), "w", stdout)
# define speed ios_base::sync_with_stdio(false);cin.tie(NULL)
# define SET(file) readfile(file);writefile(file);
# define LARGE 100005
using namespace std;
ll count_swaps( vector < int > S ) {
ll cnt = 0;
int n = S.size();
ll c = 0;
For ( i, 0, n / 2 ) {
if ( S[i] < 0 && S[i] != S[i + n / 2] && abs(S[i]) == abs(S[i + n / 2]) ) {
c++;
}
}
if ( c == n / 2 ) {
ll ans = n / 2 - 1;
ans *= n / 2;
ans /= 2;
return ans;
}
For ( i, 0, n ) {
if ( S[i] != S[i + 1] && abs(S[i]) == abs(S[i + 1]) && S[i] < 0 ) {
i++;
}
else {
For ( j, i + 1, 2 * n ) {
if ( S[i] != S[j] && abs(S[i]) == abs(S[j]) ) {
int val = S[j];
S.erase( S.begin() + j );
cnt += j - i;
vector < int > left(S.begin(), S.begin() + i);
vector < int > right( S.begin() + i, S.end() );
left.pb(val);
left.insert(left.end(), right.begin(), right.end());
S = left;
if ( S[i] > 0 ) {
swap( S[i], S[i + 1] );
cnt++;
}
break;
}
}
i++;
}
}
return cnt;
}
/*
int main() {
/// Author: _Dilshod_
speed;
vector < int > S = {2, 1, -1, -2};
cout << count_swaps(S);
}
*/
