#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T> using treap = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
#define REP(i, n) for (long long i = 0, max_i = (n); i < max_i; i++)
#define REPI(i, a, b) for (long long i = (a), max_i = (b); i < max_i; i++)
#define ALL(obj) begin(obj), end(obj)
#define RALL(obj) rbegin(obj), rend(obj)
#define fi first
#define se second
using ii = pair<int, int>;
vector<ii> dirs = {
  {1, 0}, {0, 1}, {-1, 0}, {0, -1},  // 4方向
  {1, 1}, {-1, 1}, {-1, -1}, {1, -1},  // 斜め
  {0, 0},  // 自身
};
template <class T> inline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } return false; }
template <class T> inline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; } return false; }
template <class T, class S> vector<T> make_vec(size_t n, S x) { return vector<T>(n, x); }
template <class T, class... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec<T>(ts...))>(n, make_vec<T>(ts...)); }

// debug
template <class T> ostream& operator<<(ostream& s, vector<T>& d) { REP (i, d.size()) s << d[i] << (i == d.size() - 1 ? "" : " "); return s; }
template <class T> ostream& operator<<(ostream& s, vector<vector<T>>& d) { REP (i, d.size()) s << d[i] << (i == d.size() - 1 ? "" : "\n"); return s; }
template <class T, class S> ostream& operator<<(ostream& s, pair<T, S>& p) { s << "{" << p.first << ", " << p.second << "}"; return s; }
template <class T, class S> ostream& operator<<(ostream& s, map<T, S> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
template <class T, class S> ostream& operator<<(ostream& s, unordered_map<T, S> m) { for (auto it = m.begin(); it != m.end(); it++) { s << *it << (next(it) == m.end() ? "" : "\n"); } return s; }
#ifdef _MY_DEBUG
  #define dump(...) cerr << "/* " << #__VA_ARGS__ << " :[" << __LINE__ << ":" << __FUNCTION__ << "]" << endl, dump_func(__VA_ARGS__), cerr << "*/\n\n";
#else
  #define dump(...)
  #define endl "\n"
#endif
void dump_func() { cerr << endl; }
template <class Head, class... Tail> void dump_func(Head&& h, Tail&&... t) { cerr << h << (sizeof...(Tail) == 0 ? "" : ", "), dump_func(forward<Tail>(t)...); }

struct Fast { Fast() { cin.tie(0); ios::sync_with_stdio(false); } } fast;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
constexpr int MOD = 1000000007;
// *************** TEMPLATE END *************** 

class QuickFind {
public:
  int N;
  vector<int> i2g; // 各頂点のグループ
  vector<vector<int>> g2i; // 各グループの頂点集合
  QuickFind(int n) : N(n) {
    i2g.resize(N);
    g2i = vector<vector<int>>(N, vector<int>(1));
    for (int i = 0; i < N; i++) {
      i2g[i] = i;
      g2i[i][0] = i;
    }
  }
  // iを含むグループとjを含むグループをmerge
  void merge(int i, int j) {
    int gi = i2g[i], gj = i2g[j];
    if (gi == gj) return;
    if (g2i[gi].size() < g2i[j].size()) swap(gi, gj);
    // jをiにmerge
    for (int v: g2i[gj]) i2g[v] = gi;
    g2i[gi].insert(g2i[gi].end(), ALL(g2i[gj]));
    g2i[gj].clear();
  }
  bool same(int i, int j) {
    return i2g[i] == i2g[j];
  }
};

int K = 1e5;
signed main() {
  int n; cin >> n;
  QuickFind qf(n);
  vector<int> x(n), y(n);
  REP (i, n) cin >> x[i] >> y[i], x[i]--, y[i]--;
  vector<vector<int>> xs(K), ys(K);
  REP (i, n) {
    xs[x[i]].push_back(i);
    ys[y[i]].push_back(i);
  }
  REP (x, K) {
    REP (i, (int)xs[x].size() - 1) {
      qf.merge(xs[x][i], xs[x][i + 1]);
    }
  }
  REP (y, K) {
    REP (i, (int)ys[y].size() - 1) {
      qf.merge(ys[y][i], ys[y][i + 1]);
    }
  }
  int ans = 0;
  for (auto g : qf.g2i) {
    int num = g.size();
    set<int> sx, sy;
    for (int i : g) {
      sx.insert(x[i]);
      sy.insert(y[i]);
    }
    ans += sx.size() * sy.size() - num;
  }
  cout << ans << endl;
  // vector<int> ox(n), oy(n);
  // REP (i, n) ox[i] = oy[i] = i;
  // sort(ALL(ox), [&](int i, int j) {
  //   return x[i] < x[j];
  // });
  // sort(ALL(oy), [&](int i, int j) {
  //   return y[i] < y[j];
  // });
  // vector<vector<int>> g(n);
  // REP (i, n)
  // vector<bool> visited(n);
  // REP (i, n) {
  //   int num = dfs(i);
  // }
}


Measured memory_bytes: 968168