/* Aa^~ kokoro ga pyonpyon suru n jaa^~
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*/

#include <bits/stdc++.h>
using namespace std;

using VI = vector<int>;
using VVI = vector<VI>;
using PII = pair<int, int>;
using LL = long long;
using VL = vector<LL>;
using VVL = vector<VL>;
using PLL = pair<LL, LL>;
using VS = vector<string>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define MT make_tuple
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define FF first
#define SS second

template<class S, class T>
istream& operator>>(istream& is, pair<S,T>& p){
  return is >> p.FF >> p.SS;
}
template<class T>
istream& operator>>(istream& is, vector<T>& xs){
  for(auto& x: xs)
	is >> x;
  return is;
}
template<class S, class T>
ostream& operator<<(ostream& os, const pair<S,T>& p){
  return os << p.FF << " " << p.SS;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T>& xs){
  for(unsigned int i=0;i<xs.size();++i)
	os << (i?" ":"") << xs[i];
  return os;
}
template<class T>
void maxi(T& x, T y){
  if(x < y) x = y;
}
template<class T>
void mini(T& x, T y){
  if(x > y) x = y;
}
void debug(istringstream&){}
template <char sep=',', class Head, class... Tail>
void debug(istringstream& iss, Head&& head, Tail&&... tail)
{
  string name;
  getline(iss, name, ',');
  cout << sep << name << "=" << head;
  debug(iss, forward<Tail>(tail)...);
}

#ifdef PYONPOI
#define DEBUG(...) \
  do{ \
    istringstream ss(#__VA_ARGS__); \
    debug<' '>(ss, __VA_ARGS__); \
    cout<<endl; \
  }while(0)
#else
#define DEBUG
#endif


const double EPS = 1e-10;
const double PI  = acos(-1.0);
const LL MOD = 1e9+7;

class UnionFind{
private:
  vector<int> par, rank;
public:
  UnionFind(int n){
	par.assign(n, 0);
	rank.assign(n, 0);
	for(int i=0;i<n;++i)
	  par[i] = i;
  }

  //find root of x
  int find(int x){
		if(par[x] == x)
			return x;
		return (par[x] = find(par[x]));
  }

  void unite(int x, int y){
		x = find(x);
		y = find(y);
		if(x == y) return;

		if(rank[x] < rank[y]){
			par[x] = y;
		}
		else{
			par[y] = x;
			if(rank[x] == rank[y])
			++rank[x];
		}
  }

  bool same(int x, int y){
		return find(x) == find(y);
  }
};


int main(){
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  int N;
  cin >> N;

  const int MX = 1e5+10;
  vector<vector<PII>> Gx(MX);
  vector<vector<PII>> Gy(MX);
  vector<PII> ps(N);
  REP(i,N){
    int x, y;
    cin >> x >> y;
    Gx[x].EB(y, i);
    Gy[y].EB(x, i);
    ps[i] = MP(x, y);
  }

  LL ans = 0;
#if 1
  UnionFind uf(N);
  for(auto& G : Gx){
    int p = -1;
    for(auto v : G){
      if(p >= 0)
        uf.unite(v.SS, p);
      p = v.SS;
    }
  }
  for(auto& G : Gy){
    int p = -1;
    for(auto v : G){
      if(p >= 0)
        uf.unite(v.SS, p);
      p = v.SS;
    }
  }

  VVI ids(N);
  REP(i,N){
    ids[uf.find(i)].PB(i);
  }

  for(auto& xs: ids){
    set<int> sx, sy;
    for(auto i : xs){
      sx.insert(ps[i].FF);
      sy.insert(ps[i].SS);
    }
    if(SZ(sx) > 1 && SZ(sy) > 1)
      ans += SZ(sx) * (LL)SZ(sy);
    else
      ans += SZ(xs);
  }
#else
  vector<bool> vis(N);
  REP(i,N){
    if(vis[i]) continue;
    queue<int> qx, qy;
    set<int> sx, sy;
    qx.push(ps[i].FF);
    qy.push(ps[i].SS);
    sx.insert(ps[i].FF);
    sy.insert(ps[i].SS);
    set<int> crt;
    crt.insert(i);

    while(!qx.empty() || !qy.empty()){
      if(!qx.empty()){
        int x = qx.front();
        qx.pop();
        for(auto v : Gx[x]){
          int yy = v.FF;
          if(!sy.count(yy)){
            qy.push(yy);
            sy.insert(yy);
            vis[v.SS] = true;
            crt.insert(v.SS);
          }
        }
      }
      if(!qy.empty()){
        int y = qy.front();
        qy.pop();
        for(auto v : Gy[y]){
          int xx = v.FF;
          if(!sx.count(xx)){
            qx.push(xx);
            sx.insert(xx);
            vis[v.SS] = true;
            crt.insert(v.SS);
          }
        }
      }
    }

    if(SZ(sx) > 1 && SZ(sy) > 1)
      ans += (LL)SZ(sy) * (LL)SZ(sx);
    else
      ans += SZ(crt);
  }
#endif
  cout << ans - N << endl;

  return 0;
}

Measured memory_bytes: 17532