#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
#define int long long
void remove(set<int>&lef, vector<set<int>>&pos, vector<signed>&s, int p) {
if (s[p] < 0) lef.erase(p);
else pos[s[p]].erase(p);
if (s[p + 1] < 0) lef.erase(p + 1);
else pos[s[p + 1]].erase(p + 1);
}
void add(set<int>&lef, vector<set<int>>&pos, vector<signed>&s, int p) {
if (s[p] < 0) lef.insert(p);
else pos[s[p]].insert(p);
if (s[p + 1] < 0) lef.insert(p + 1);
else pos[s[p + 1]].insert(p + 1);
}
long long count_swaps(std::vector<signed> s) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
set<int> lef, rig;
int n = s.size()/2;
vector<set<int>> pos(n + 5);
for (int i = 0; i < 2*n; i++) {
if (s[i] > 0) pos[s[i]].insert(i);
if (s[i] < 0) lef.insert(i);
}
int ans = 0, index = 0;
while (index < 2*n) {
int l = *lef.begin();
for (int i = l - 1; i >= index; i--) {
remove(lef, pos, s, i);
swap(s[i], s[i + 1]);
add(lef, pos, s, i);
ans++;
}
lef.erase(index);
int r = *pos[-s[index]].begin();
index++;
for (int i = r - 1; i >= index; i--) {
remove(lef, pos, s, i);
swap(s[i], s[i + 1]);
add(lef, pos, s, i);
ans++;
}
pos[s[index]].erase(index);
index++;
}
return ans;
}
/*signed main() {
int n;
cin >> n;
vector<signed> arr(2*n);
for (int i = 0; i < 2*n; i++) cin >> arr[i];
cout << count_swaps(arr) << '\n';
return 0;
}*/
