#include <bits/stdc++.h>
using namespace std;

#define REP(i,a) for (int i = 0; i < a; i++)
#define FOR(i,a,b) for (int i = a; i <= b; i++)
#define ROF(i,a,b) for (int i = a; i >= b; i--)
#define FOREACH(it,x) for (__typeof((x).begin()) it = (x).begin(); it != (x).end(); it++)
#define all(x) (x).begin(),(x).end()
#define UNIQUE(x) sort(all(x)),(x).erase(unique(all(x)),(x).end())
#define ll long long
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define pii pair<int,int>
#define SZ(x) ((int)(x).size())

int a[100001];
int AIB[100001];

void update(int Val,int idx){
    for(;idx <= 100000; idx += (idx & -idx))
        AIB[idx] += Val;
}

int query(int idx){
    int sum = 0;
    for(;idx>0; idx-=(idx & -idx))
        sum += AIB[idx];
    return sum;
}

int Query(int l,int r) {
    if (r < l) return 0;
    return query(r) - query(l-1);
}

int First[50001];

int main()
{
    ios_base::sync_with_stdio(false);
    int n;
    cin >> n;
    FOR(i,1,2*n) cin >> a[i];
    int Pos = 0;
    ll Sum = 0;
    FOR(i,1,2*n) {
        if (!First[a[i]]) {
            ++Pos;
            First[a[i]] = Pos;
            update(1,Pos);
        }
        else {
            int q = Query(First[a[i]]+1,Pos);
            Sum += q;
            update(-1,First[a[i]]);
        }
    }
    cout << Sum;
}