#include <bits/stdc++.h>
using namespace std;
const int N = 2e2 + 5;
int read() {
  int s = 0;
  char c = getchar(), lc = '+';
  while (c < '0' || '9' < c) lc = c, c = getchar();
  while ('0' <= c && c <= '9') s = s * 10 + c - '0', c = getchar();
  return lc == '-' ? -s : s;
}
void write(int x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x < 10)
    putchar(x + '0');
  else {
    write(x / 10);
    putchar(x % 10 + '0');
  }
}
void print(int x, char c = '\n') {
  write(x);
  putchar(c);
}
int a[N], b[N];
signed main() {
  int n = read(), ans = 0;
  for (int i = 1; i <= n * 2; i++) a[i] = read();
  for (int i = 1; i <= n * 2; i++)
    if (b[a[i]]) {
      int now = i;
      while (a[now] != a[now - 1]) {
        swap(a[now], a[now - 1]);
        now--;
        ans++;
      }
    } else
      b[a[i]] = 1;
  print(ans);
  return 0;
}
