#include "bits/stdc++.h"
using namespace std;
using ll = long long;
using vll = std::vector<ll>;
using vvll = std::vector<vll>;
using vvvll = std::vector<vvll>;
using dd = double;
using vdd = std::vector<dd>;
using vvdd = std::vector<vdd>;
using vvvdd = std::vector<vvdd>;

constexpr ll INF = 1LL << 60;
constexpr dd EPS = 1e-11;

typedef std::numeric_limits< double > dbl;

//cin,cout高速化のおまじない＋桁数指定
struct Fast{
	Fast(){
		cin.tie(0);
		ios::sync_with_stdio(false);
		cout << fixed << setprecision(std::numeric_limits<double>::max_digits10);
	}
} fast;

#define REPS(i, S, E) for (ll i = (S); i <= (E); i++)
#define REP(i, N) REPS(i, 0, N-1)
#define DEPS(i, E, S) for (ll i = (E); i >= (S); i--)
#define DEP(i, N) DEPS(i, N-1, 0)
#define EACH(e, v) for (auto&& e : v)

template<class T> inline bool chmax(T &a, T b) { if (a < b) { a = b; return true; }return false; }
template<class T> inline bool chmin(T &a, T b) { if (a > b) { a = b; return true; }return false; }
template<class T> inline T MaxE(vector<T> &v, ll S, ll E){ T m=v[S]; REPS(i, S, E)chmax(m, v[i]); return m; }//v[S]～v[E]の最大値
template<class T> inline T MinE(vector<T> &v, ll S, ll E){ T m=v[S]; REPS(i, S, E)chmin(m, v[i]); return m; }//v[S]～v[E]の最小値
template<class T> inline T MaxE(vector<T> &v, ll N) { return MaxE(v, 0, N - 1); } //先頭N個中の最大値
template<class T> inline T MinE(vector<T> &v, ll N) { return MinE(v, 0, N - 1); }
template<class T> inline T MaxE(vector<T> &v) { return MaxE(v, (ll)v.size()); }
template<class T> inline T MinE(vector<T> &v) { return MinE(v, (ll)v.size()); }
template<class T> inline ll MaxI(vector<T> &v, ll S, ll E){ ll m=S; REPS(i, S, E){ if (v[i]>v[m])m=i; }return m; }
template<class T> inline ll MinI(vector<T> &v, ll S, ll E){ ll m=S; REPS(i, S, E){ if (v[i]<v[m])m=i; }return m; }
template<class T> inline ll MaxI(vector<T> &v, ll N) { return MaxI(v, 0, N - 1); }
template<class T> inline ll MinI(vector<T> &v, ll N) { return MinI(v, 0, N - 1); }
template<class T> inline ll MaxI(vector<T> &v) { return MaxI(v, (ll)v.size()); }
template<class T> inline ll MinI(vector<T> &v) { return MinI(v, (ll)v.size()); }
template<class T> inline T Sum(vector<T> &v, ll S, ll E){ T s=v[S]; REPS(i, S+1, E)s+=v[i]; return s; }
template<class T> inline T Sum(vector<T> &v, ll N) { return Sum(v, 0, N - 1); }
template<class T> inline T Sum(vector<T> &v) { return Sum(v, v.size()); }

//剰余計算用クラス
constexpr ll MOD = (ll)(1e9 + 7); // 998244353L;
template<int mod> struct Modll{
	ll val;
	Modll(ll v = 0): val(v % mod){
		if (val < 0) val += mod;
	}
	Modll operator - () { return -val; }
	Modll operator + (const Modll &b) const {return val + b.val;}
	Modll operator - (const Modll &b) const {return val - b.val;}
	Modll operator * (const Modll &b) const {return val * b.val;}
	Modll operator / (const Modll &b) const {return Modll(*this) /= b; }
	Modll operator + (ll b) const { return *this + Modll(b); }
	Modll operator - (ll b) const { return *this - Modll(b); }
	Modll operator * (ll b) const { return *this * Modll(b); }
	friend Modll<mod> operator + (ll a, const Modll<mod> &b) { return b + a; }
	friend Modll<mod> operator - (ll a, const Modll<mod> &b) { return -b + a; }
	friend Modll<mod> operator * (ll a, const Modll<mod> &b) { return b * a; }
	Modll &operator += (const Modll &b) { val=(val+b.val)%mod; return *this; }
	Modll &operator -= (const Modll &b) { val=(val+mod-b.val)%mod; return *this; }
	Modll &operator *= (const Modll &b) { val=(val*b.val)%mod; return *this; }
	Modll &operator /= (const Modll &b) {
		ll c=b.val, d=mod, u=1, v=0;
		while (d){
			ll t = c / d;
			c -= t * d; swap(c, d);
			u -= t * v; swap(u, v);
		}
		val = val * u % mod;
		if (val < 0) val += mod;
		return *this;
	}
	Modll &operator += (ll b) { return *this += Modll(b); }
	Modll &operator -= (ll b) { return *this -= Modll(b); }
	Modll &operator *= (ll b) { return *this *= Modll(b); }
	Modll &operator /= (ll b) { return *this /= Modll(b); }
	bool operator == (const Modll &b) { return val == b.val; }
	bool operator != (const Modll &b) { return val != b.val; }
	bool operator == (ll b) { return *this == Modll(b); }
	bool operator != (ll b) { return *this != Modll(b); }
	friend bool operator == (ll a, const Modll<mod> &b) { return Modll<mod>(a) == b.val; }
	friend bool operator != (ll a, const Modll<mod> &b) { return Modll<mod>(a) != b.val; }
	friend ostream &operator << (ostream &os, const Modll<mod> &a) { return os << a.val; }
	friend istream &operator >> (istream &is, const Modll<mod> &a) { return is >> a.val; }
	Modll pow(ll n){
		if (n == 0) return 1;
		auto b = pow(n / 2);
		return (n%2 == 1) ? b*b*val : b*b;
	}
};
using modll = Modll<MOD>;

template<class T=ll> inline vector<T> cinv(ll N){ vector<T> v(N); REP(i, N)cin>>v[i]; return move(v); }
template<class T=ll, class S=ll> inline vector<pair<T, S>> cinv2(ll N){
	vector<pair<T, S>> v(N); REP(i,N){cin>>v[i].first>>v[i].second;} return move(v); }


class UnionFindTree{
private:
	vll par;
	vll rank;
public:
	UnionFindTree(ll num): par(num), rank(num) { REP(i, num) par[i] = i; }
	bool same(ll x, ll y) { return root(x) == root(y); }
	ll root(ll x) { return (par[x] == x) ? x : par[x]=root(par[x]); }
	void unite(ll x, ll y){
		x = root(x);
		y = root(y);
		if (x == y) return;
		if (rank[x] < rank[y]) par[x] = y;
		else                   par[y] = x;
		if (rank[x] == rank[y]) rank[x]++;
	}
};

vector<pair<ll, ll>> xy;

int main()
{
	ll N;
	cin>>N;
	vector<pair<ll, ll>> xy = cinv2(N);

	vector<tuple<ll, ll, ll>> xyidx;
	REP(i, N){
		xyidx.emplace_back(xy[i].first, xy[i].second, i);
	}
	auto xyidx_xsort = xyidx;
	auto xyidx_ysort = xyidx;

	std::sort(xyidx_xsort.begin(), xyidx_xsort.end(),
		[](auto &a, auto &b) { return get<0>(a) < get<0>(b); }
	);
	std::sort(xyidx_ysort.begin(), xyidx_ysort.end(),
		[](auto &a, auto &b) { return get<1>(a) < get<1>(b); }
	);

	UnionFindTree uft(N);
	REP(i, N-1){
		auto &enow = xyidx_xsort[i];
		auto &enxt = xyidx_xsort[i+1];
		if (get<0>(enow) == get<0>(enxt)){
			uft.unite(get<2>(enow), get<2>(enxt));
		}
	}
	REP(i, N-1){
		auto &enow = xyidx_ysort[i];
		auto &enxt = xyidx_ysort[i+1];
		if (get<1>(enow) == get<1>(enxt)){
			uft.unite(get<2>(enow), get<2>(enxt));
		}
	}

	unordered_map<ll, vll> grps;
	REP(i, N){
		ll r = uft.root(i);
		grps[r].push_back(i);
	}

	ll ans = 0;
	EACH(e, grps){
		auto grp = e.second;
		if (grp.size() <= 2) continue;

		std::unordered_set<ll> xpos;
		std::unordered_set<ll> ypos;
		xpos.reserve(grp.size());
		ypos.reserve(grp.size());
		EACH(idx, grp){
			auto x = xy[idx].first;
			auto y = xy[idx].second;
			xpos.insert(x);
			ypos.insert(y);
		}
		ans += xpos.size() * ypos.size() - grp.size();
	}

	cout << ans << '\n';

	return 0;
}


Measured memory_bytes: 16880