// When she's prettier than any DP you've ever seen...
#include <bits/stdc++.h>
using namespace std;
const int baza = (1<<18); int d[2*baza];
int pierwszy() {
int v = 1;
while (v < baza)
v = ((d[2*v] > 0) ? 2*v : 2*v+1);
return v-baza;
}
void akt(int i) {
i = (i+baza)/2;
while (i > 0)
d[i] = d[2*i]+d[2*i+1], i /= 2;
}
int suma(int l, int r) {
int wynik = 0; l += baza-1, r += baza+1;
while (l/2 != r/2) {
if (l%2 == 0)
wynik += d[l+1];
if (r%2 == 1)
wynik += d[r-1];
l /= 2, r /= 2;
}
return wynik;
}
long long count_swaps(vector<int> S)
{
int n = S.size()/2;
vector<int> ind[n+1][2];
for (int i = 2*n-1; i >= 0; i--) {
d[i+baza] = 1;
if (S[i] < 0)
ind[-S[i]][0].push_back(i);
else
ind[S[i]][1].push_back(i);
}
for (int i = baza-1; i > 0; i--)
d[i] = d[2*i]+d[2*i+1];
long long odp = 0;
while (d[1] > 0) {
int x = pierwszy(), y;
if (S[x] > 0)
y = ind[S[x]][0].back(), odp++;
else
y = ind[-S[x]][1].back();
ind[abs(S[x])][0].pop_back(), ind[abs(S[x])][1].pop_back();
d[x+baza] = d[y+baza] = 0, akt(x), akt(y), odp += suma(x,y);
}
return odp;
}
