#include <bits/stdc++.h>   using namespace std;   int32_t main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     long long n;     cin >> n;     long long arr[2 * n];     for (long long i = 0; i < 2 * n; i++) cin >> arr[i];     long long m = 0;     for (long long i = 0; i < 2 * n; i++) {       if (arr[i] != arr[i + 1]) {         for (long long j = i + 1; j < 2 * n; j++) {           if (arr[i] == arr[j]) {             for (long long k = j; k > i + 1; k--) {               swap(arr[k], arr[k - 1]);               m++;             }             break;           }         }         i++;       } else         i++;     }     cout << m;   }   