#include<bits/stdc++.h>
//#define name "InvMOD"
#ifndef name
#include "shoes.h"
#endif // name
using namespace std;
#define sz(v) (int)(v).size()
using ll = long long;
// 2i : left shoe, 2i + 1: right shoe
// x < 0 -> left shoe, x > 0 -> right shoe
struct BIT{
vector<int> bit;
BIT(int n = 0): bit(n + 1) {}
void update(int p, int val){
for(; p < sz(bit); p += (p & (-p))){
bit[p] += val;
}
return;
}
int get(int p){
if(p < 0) return 0;
int res = 0;
for(; p > 0; p -= (p & (-p))){
res += bit[p];
}
return res;
}
int query(int l, int r){
if(l > r) return 0;
return get(r) - get(l - 1);
}
};
ll count_swaps(vector<int> S){
BIT bit(sz(S)); map<int, vector<int>> ppos;
for(int i = sz(S) - 1; i >= 0; i--)
ppos[S[i]].push_back(i);
vector<bool> vis(sz(S), false);
ll answer = 0;
for(int i = 0; i < sz(S); i++){
if(!sz(ppos[S[i]]) || ppos[S[i]].back() != i) continue;
int nxt_pos = ppos[-S[i]].back();
answer = answer + (nxt_pos - i - (S[i] < 0)) - bit.query(i + 1, nxt_pos);
bit.update(nxt_pos, 1);
ppos[-S[i]].pop_back(), ppos[S[i]].pop_back();
}
return answer;
}
#ifdef name
int32_t main(){
freopen(name".INP", "r", stdin);
freopen(name".OUT", "w", stdout);
int n; cin >> n;
vector<int> S(2 * n);
for(int i = 0; i < 2 * n; i++){
cin >> S[i];
}
cout << count_swaps(S) << "\n";
return 0;
}
#endif // name
/*
Input:
2
2 1 -1 -2
Ex:
2 1 -2 -1
2 -2 1 -1
-2 2 1 -1
-2 2 -1 1
Input:
3
-2 2 2 -2 -2 2
*/
