#include <iostream>
#include <cstdio>

using namespace std;

int aib[100004];
int N;
int freq[100004];

void update(int pos, int value) {
    for(;pos <= 2 * N; pos += pos & (-pos)) {
        aib[pos] += value;
    }
}

int query(int pos) {
    int ans = 0;

    for(;pos;pos -= pos & (-pos)) {
        ans += aib[pos];
    }

    return ans;
}

int main() {
    #ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    #endif // ONLINE_JUDGE

    cin >> N;

    int ans = 0;
    int x;
    for(int i = 1; i <= 2 * N; ++i) {
        cin >> x;

        if(freq[x] == 0) {
            freq[x] = i;
            update(i, 1);
        }
        else {
            update(freq[x], -1);
            ans += query(i) - query(freq[x]);
            freq[x] = 0;
        }
    }

    cout << ans << '\n';

    return 0;
}