#ifdef DEBUG_IS_VALID
#define DEB 1 
#define _LIBCPP_DEBUG 0
#else
#define DEB 0
#define NDEBUG
#endif

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

#define ALL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define RREP(i, x, n) for(int i = x; i >= n; i--)
#define rrep(i, n) RREP(i,n,0)
#define pb push_back
#pragma GCC optimize ("-O3")

using namespace std;

#define DUMPOUT cout
#define dump(...) if(DEB) DUMPOUT<<"  "<<#__VA_ARGS__<<" :["<<__LINE__<<":"<<__FUNCTION__<<"]"<<endl<<"    "; if(DEB) dump_func(__VA_ARGS__)
template<typename T1,typename T2>ostream& operator << (ostream& os, pair<T1,T2> p){cout << "(" << p.first << ", " << p.second << ")"; return os;}
template<typename T>ostream& operator << (ostream& os, vector<T>& vec) { os << "{"; for (int i = 0; i<vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : ", "); os << "}"; return os; }
template<typename T>ostream& operator << (ostream& os, set<T>& st){cout << "{"; for(auto itr = st.begin(); itr != st.end(); itr++) cout << *itr << (next(itr)!=st.end() ? ", " : ""); cout << "}"; return os;}
template<typename T1,typename T2>ostream& operator << (ostream& os, map<T1,T2> mp){cout << "{"; for(auto itr = mp.begin(); itr != mp.end(); itr++) cout << "(" << (itr->first) << ", " << (itr->second) << ")" << (next(itr)!=mp.end() ? "," : ""); cout << "}"; return os; }

void dump_func(){DUMPOUT << endl;}
template <class Head, class... Tail>void dump_func(Head&& head, Tail&&... tail){ DUMPOUT << head; if (sizeof...(Tail) == 0) { DUMPOUT << " "; } else { DUMPOUT << ", "; } dump_func(std::move(tail)...);}
template<class T> inline bool chmax(T& a,T const& b){if(a>=b) return false; a=b; return true;}
template<class T> inline bool chmin(T& a,T const& b){if(a<=b) return false; a=b; return true;}

using ll = long long;
using P = pair<int,int>;
using Pl = pair<ll,ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vp = vector<Pl>;
using vvp = vector<vp>;

const int INF = 1<<29;
const long long LINF=1LL<<59;

struct UnionFindTree{
  vector<int> par,rank,size;
  UnionFindTree(int N){
    par = rank = vector<int>(N,0);
    size = vector<int>(N,1);
    for(int i = 0; i < N; i++) par[i] = i;
  }
  int find(int x){
    if(par[x] == x) return x;
    else 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];
    }
    size[x] = size[y] = size[x] + size[y];
  }
  bool same(int x,int y){
    return find(x) == find(y);
  }
};

ll part(vi& vec,vl& x,vl& y){
  bool ok = false;
  map<ll,ll> xs,ys;
  for(auto& i:vec){
    xs[x[i]]++;
    ys[y[i]]++;
  }
  for(auto& i:vec){
    if(xs[x[i]]>=2 && ys[y[i]]>=2) ok = true;
  }
  if(ok) return ll(xs.size())*ll(ys.size())-ll(vec.size());
  return 0LL;
}

void solve(long long N, std::vector<long long> x, std::vector<long long> y){
  UnionFindTree uft(N);
  map<ll,vector<int>> xmp,ymp;
  rep(i,N){
    xmp[x[i]].pb(i);
    ymp[y[i]].pb(i);
  }
  for(auto&& p:xmp){
    auto&& vec = p.second;
    rep(i,vec.size()-1){
      uft.unite(vec[i],vec[i+1]);
    }
  }
  for(auto&& p:ymp){
    auto&& vec = p.second;
    rep(i,vec.size()-1){
      uft.unite(vec[i],vec[i+1]);
    }
  }
  vvi g(N);
  rep(i,N) g[uft.find(i)].pb(i);
  ll ans = 0;
  rep(i,N){
    if(g[i].size()){
      ans += part(g[i],x,y);
    }
  }
  cout << ans << endl;
}

int main(){
  long long N;
  scanf("%lld",&N);
  std::vector<long long> x(N);
  std::vector<long long> y(N);
  for(int i = 0 ; i < N ; i++){
    scanf("%lld",&x[i]);
    scanf("%lld",&y[i]);
  }
  solve(N, std::move(x), std::move(y));
  return 0;
}


Measured memory_bytes: 22908