#include "shoes.h"
#include <cmath>
#include <cstdlib>
#include <cassert>
long long count_swaps(std::vector<int> s) {
using ll = long long;
using namespace std;
ll n = (int)s.size(); n /= 2;
vector<vector<ll>> pos(n, vector<ll>()), neg(n, vector<ll>());
for (int i = 0; i < 2 * n; i++) {
ll x = abs(s[i]);
if (s[i] < 0) {
neg[x - 1].push_back(i);
} else {
pos[x - 1].push_back(i);
}
}
ll op_1 = 0, op_2 = 0;
for (int i = 0; i < n; i++) {
assert(neg[i].size() == pos[i].size());
for (int j = 0; j < (int)neg[i].size(); j++) {
int x = neg[i][j], y = pos[i][j];
op_1 += abs(x - y) - 1;
if (x > y) op_2++;
}
}
op_1 /= 2;
return op_1 + op_2;
}
