source_code: import com.sun.org.apache.xerces.internal.util.SynchronizedSymbolTable;
  import jdk.management.cmm.SystemResourcePressureMXBean;
  
  import java.awt.*;
  import java.io.*;
  import java.lang.reflect.Array;
  import java.text.DecimalFormat;
  import java.util.*;
  import java.util.List;
  import java.math.*;
  
  public class Newbie {
  
      static InputReader sc = new InputReader(System.in);
      static PrintWriter out = new PrintWriter(System.out);
  
      public static void main(String[] args) {
          solver s = new solver();
          int t = 1;
          while (t > 0) {
              s.solve();
              t--;
          }
          out.close();
      }
  
     /* static class descend implements Comparator<pair1> {
          public int compare(pair1 o1, pair1 o2) {
              if (o1.pop != o2.pop)
                  return (int) (o1.pop - o2.pop);
              else
                  return o1.in - o2.in;
          }
      }*/
  
      static class InputReader {
          public BufferedReader br;
          public StringTokenizer token;
  
          public InputReader(InputStream stream) {
              br = new BufferedReader(new InputStreamReader(stream), 32768);
              token = null;
          }
  
          public String next() {
              while (token == null || !token.hasMoreTokens()) {
                  try {
                      token = new StringTokenizer(br.readLine());
                  } catch (IOException e) {
                      throw new RuntimeException(e);
                  }
              }
              return token.nextToken();
          }
  
          public int nextInt() {
              return Integer.parseInt(next());
          }
  
          public long nextLong() {
              return Long.parseLong(next());
          }
  
          public double nextDouble() {
              return Double.parseDouble(next());
          }
      }
  
      static class card {
          long a;
          int cnt;
          int i;
  
          public card(long a, int cnt, int i) {
              this.a = a;
              this.cnt = cnt;
              this.i = i;
          }
      }
  
      static class ascend implements Comparator<pair> {
          public int compare(pair o1, pair o2) {
              return o1.a - o2.a;
          }
      }
  
      static class extra {
  
          static boolean v[] = new boolean[100001];
          static List<Integer> l = new ArrayList<>();
          static int t;
  
          static void shuffle(long a[]) {
              List<Long> l = new ArrayList<>();
              for (int i = 0; i < a.length; i++)
                  l.add(a[i]);
              Collections.shuffle(l);
              for (int i = 0; i < a.length; i++)
                  a[i] = l.get(i);
          }
  
          static long gcd(long a, long b) {
              if (b == 0)
                  return a;
              else
                  return gcd(b, a % b);
          }
  
          static boolean valid(int i, int j, int r, int c) {
              if (i >= 0 && i < r && j >= 0 && j < c)
                  return true;
              else
                  return false;
          }
  
          static void seive() {
              for (int i = 2; i < 100001; i++) {
                  if (!v[i]) {
                      t++;
                      l.add(i);
                      for (int j = 2 * i; j < 100001; j += i)
                          v[j] = true;
                  }
              }
          }
  
          static int binary(long a[], long val, int n) {
              int mid = 0, l = 0, r = n - 1, ans = 0;
              while (l <= r) {
                  mid = (l + r) >> 1;
                  if (a[mid] == val) {
                      r = mid - 1;
                      ans = mid;
                  } else if (a[mid] > val)
                      r = mid - 1;
                  else {
                      l = mid + 1;
                      ans = l;
                  }
              }
              return (ans + 1);
          }
  
          static long fastexpo(int x, int y) {
              long res = 1;
              while (y > 0) {
                  if ((y & 1) == 1) {
                      res *= x;
                  }
                  y = y >> 1;
                  x = x * x;
              }
              return res;
          }
  
          static long lfastexpo(int x, int y, int p) {
              long res = 1;
              x = x % p;
              while (y > 0) {
                  if ((y & 1) == 1) {
                      res = (res * x) % p;
                  }
                  y = y >> 1;
                  x = (x * x) % p;
              }
              return res;
          }
      }
  
      static class pair {
          int a;
          int b;
  
          public pair(int a, int i) {
              this.a = a;
              this.b = i;
          }
      }
  
      static class pair1 {
          pair p;
          int in;
  
          public pair1(pair a, int n) {
              this.p = a;
              this.in = n;
          }
      }
  
      static long m = (long) 1e9 + 7;
  
      static class solver {
          void solve() {
              int n = sc.nextInt();
              int ans=0;
              int a[]=new int[2*n];
              for (int i = 0; i < 2 * n; i++) {
                 a[i]=sc.nextInt();
              }
              for(int i=0;i<2*n;i++)
              {
                  if(a[i]>0)
                  {
                      int j=0;
                      for(j=i+1;a[i]!=a[j];j++)
                      {
                          if(a[j]>0)
                              ans++;
                      }
                      a[j]=0;
                  }
              }
              System.out.println(ans);
          }
      }
  }