#include <cstdio>
#include <cassert>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
vector<ll> st(8e5+5, 0);
void update(ll l, ll r, ll ind, ll pos){
if(l == r){st[ind]++; return;}
ll m = (l+r)/2;
if(pos<=m){
update(l, m, 2*ind, pos);
} else {
update(m+1, r, 2*ind+1, pos);
}
st[ind] = st[2*ind] + st[2*ind+1];
}
ll query(ll l, ll r, ll ind, ll ql, ll qr){
if(r<ql or qr<l){return 0;}
if(ql<=l and r<=qr){return st[ind];}
ll m = (l+r)/2;
return query(l, m, 2*ind, ql, qr) + query(m+1, r, 2*ind+1, ql, qr);
}
ll count_swaps(vector<int> s) {
ll inv = 0;
ll n = s.size();
n = n/2;
vector<pair<ll, ll>> a;
vector<queue<ll>> q(n+1);
for(ll i=0;i<2*n;i++){
if(s[i]<0){
a.push_back({s[i], i});
a.push_back({-s[i], -1});
} else {
q[s[i]].push(i);
}
}
for(ll i=0;i<2*n;i++){
if(a[i].first > 0){
a[i].second = q[a[i].first].front();
q[a[i].first].pop();
}
}
for(ll i=0;i<2*n;i++){
inv += query(0, 2*n-1, 1, a[i].second, 2*n-1);
update(0, 2*n-1, 1, a[i].second);
}
return inv;
}
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;
}
