#include<bits/stdc++.h>
using namespace std;
long long count_swaps(vector<int> s) {
int n = s.size();
int vis[n] = {};
int ans = 0;
for (int i = 0; i < n; i++) {
for (int j = i - 1; j >= 0; j--) {
if (s[j] == -s[i] && !vis[j]) {
if (s[j] < 0)
ans--;
ans += i - j;
vis[i] = 1;
vis[j] = 1;
break;
}
}
}
return ans;
}
#include "shoes.h"
// int main() {int n;assert(1 == scanf("%d", &n));vector<int> S(2 * n);for (int i = 0; i < 2 * n; i++)assert(1 == scanf("%d", &S[i]));fclose(stdin);long long result = count_swaps(S);printf("%lld\n", result);fclose(stdout);return 0;}
