#pragma region header
#include <bits/stdc++.h>
#define int long long
#define all(a) begin(a), end(a)
#define rall(a) rbegin(a), rend(a)
#define mp make_pair
#define mt make_tuple
#define rep1(i, n) for (decltype(+n) i = 0; i < (n); i++)
#define rrep1(i, n) for (auto i = n - 1; i > static_cast<decltype(i)>(-1); i--)
#define rep2(i, a, b) for (auto i = (a); i < (b); i++)
#define rrep2(i, a, b) for (auto i = b - 1; i >= a; i--)
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep2, rep1) (__VA_ARGS__)
#define rrep(...) GET_MACRO(__VA_ARGS__, rrep2, rrep1) (__VA_ARGS__)
#define each(i, a) for (auto &&i : (a))
using namespace std;

using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;
using vvs = vector<vs>;
using vd = vector<ld>;
using vvd = vector<vd>;
using vb = vector<bool>;
using vvb = vector<vb>;
using pii = pair<int, int>;
using vp = vector<pii>;
using vvp = vector<vp>;
using mii = map<int, int>;
using vm = vector<mii>;
using vvm = vector<vm>;
template <class T>
using less_queue = priority_queue<T>;
template <class T>
using greater_queue = priority_queue<T, vector<T>, greater<T>>;

constexpr int INF = 1e18;

template <class T>
void SORT(T &a) { stable_sort(all(a)); }
template <class T>
void RSORT(T &a) { stable_sort(rall(a)); }
template <class T>
void rev(T &a) { reverse(rall(a)); }
template <class T>
void uniq(T &a) { a.erase(unique(all(a)), end(a)); }
template <class T>
auto min_of(T a) { return *min_element(all(a)); }
template <class T>
auto max_of(T a) { return *max_element(all(a)); }
template <class T>
int sum_of(T a) { return accumulate(all(a), 0ll); }
template <class T, class U>
auto sum_of(T a, U init) { return accumulate(all(a), init); }
template <class T, class U>
int count_of(T a, U i) { return count(all(a), i); }
template <class T, class U>
bool has(T a, U i) { return find(all(a), i) != end(a); }
template <class T>
int sz(T a) { return a.size(); };

template <class T>
void COUT(T x) { cout << x << endl; }
template <class T, class U>
void COUT(T x, U y) { cout << x << ' ' << y << endl; }
template <class T, class U, class V>
void COUT(T x, U y, V z) { cout << x << ' ' << y << ' ' << z << endl; }
template <class T>
void CSP(T x) { cout << x << ' '; }
template <class T>
void CVEC(T v) {
  int c = v.size() - 1;
  for (size_t i = 0; i < c; i++) cout << v[i] << ' ';
  if (c > -1) cout << v[c];
  cout << endl;
}

template <class T>
bool amin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
bool amax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

int ceil_div(int x, int y) { return (x - 1) / y + 1; }

#pragma endregion header

// no MOD
struct union_find {
  vi data;
  union_find(int size) : data(size, -1) {}
  bool union_set(int x, int y) {
    x = root(x);
    y = root(y);
    if (x != y) {
      if (data[y] < data[x]) swap(x, y);
      data[x] += data[y];
      data[y] = x;
    }
    return x != y;
  }
  bool find_set(int x, int y) { return root(x) == root(y); }
  int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
  int size(int x) { return -data[root(x)]; }
};

template <class T>
vector<pair<T, int>> zip_vi(vector<T> v) {
  int n = sz(v);
  vector<pair<T, int>> w(n);
  for (int i = 0; i < n; i++) w[i] = make_pair(v[i], i);
  return w;
}
template <class T>
vector<pair<int, T>> zip_iv(vector<T> v) {
  int n = sz(v);
  vector<pair<int, T>> w(n);
  for (int i = 0; i < n; i++) w[i] = make_pair(i, v[i]);
  return w;
}
template <class T, class S>
vector<pair<T, S>> zip(vector<T> v, vector<S> w) {
  int n = min(sz(v), sz(w));
  vector<pair<T, S>> x(n);
  for (int i = 0; i < n; i++) x[i] = make_pair(v[i], w[i]);
  return x;
}
template <class T, class S>
pair<vector<T>, vector<S>> unzip(vector<pair<T, S>> v) {
  int n = sz(v);
  auto w = make_pair(vector<T>(n), vector<S>(n));
  for (int i = 0; i < n; i++) {
    w.first[i] = v[i].first;
    w.second[i] = v[i].second;
  }
  return w;
}
template <class T, class S>
vector<T> unzip_first(vector<pair<T, S>> v) {
  int n = sz(v);
  vector<T> w(n);
  for (int i = 0; i < n; i++) w[i] = v[i].first;
  return w;
}
template <class T, class S>
vector<S> unzip_second(vector<pair<T, S>> v) {
  int n = sz(v);
  vector<S> w(n);
  for (int i = 0; i < n; i++) w[i] = v[i].second;
  return w;
}

void solve(int N, vi x, vi y) {
  union_find uf(N);
  vp xi = zip_vi(x);
  SORT(xi);
  rep(i, N - 1)if(xi[i].first == xi[i + 1].first)
    uf.union_set(xi[i].second, xi[i + 1].second);
  vp yi = zip_vi(y);
  SORT(yi);
  rep(i, N - 1)if(yi[i].first == yi[i + 1].first)
    uf.union_set(yi[i].second, yi[i + 1].second);
  unordered_map<int, unordered_set<int>> xs, ys;
  rep(i, N) {
    int r = uf.root(i);
    xs[r].insert(x[i]);
    ys[r].insert(y[i]);
  }
  int ans = 0;
  each(p, xs) {
    int r = p.first;
    int xn = sz(p.second), yn = sz(ys[r]);
    if(xn == 1 || yn == 1)continue;
    ans += xn * yn - uf.size(r);
  }
  COUT(ans);
}


#pragma region main
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed << setprecision(15);

  int N;
  cin >> N;
  vi x(N);
  vi y(N);
  for(int i = 0 ; i < N ; i++){
    cin >> x[i];
    cin >> y[i];
  }
  solve(N, move(x), move(y));
}
#pragma endregion main


Measured memory_bytes: 14932