#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int n;
vector<int> config;
ll mn = LLONG_MAX;
void shoes(int i, ll swaps) {
if (i == n - 1) {
// for (int x: config) cout << x << " ";
// cout << "\n";
bool valid = true;
for (int i = 0; i < n; i += 2) {
if (abs(config[i]) != config[i + 1]) {
valid = false;
break;
}
}
if (valid) mn = min(mn, swaps);
return;
}
swap(config[i], config[i + 1]);
shoes(i + 1, swaps + 1);
swap(config[i], config[i + 1]);
shoes(i + 1, swaps);
}
ll count_swaps(vector<int> s) {
n = s.size();
config = s;
shoes(0, 0);
return mn;
}
