#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;

#define REP(i,n) for(long long i = 0; i < (n); i++)
#define FOR(i, m, n) for(long long i = (m);i < (n); ++i)
#define ALL(obj) (obj).begin(),(obj).end()

template<class T> using V = vector<T>;
template<class T, class U> using P = pair<T, U>;

const ll MOD = (ll)1e9 + 7;
const ll MOD2 = 998244353;
const ll LLINF = (ll)1e18;
const ll INTINF = (ll)1e9;
const long double PI = 3.1415926535897932384626433;

template <class T> void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}}
template <class T, class U>ostream &operator<<(ostream &o, const map<T, U>&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;}
template <class T>ostream &operator<<(ostream &o, const set<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const multiset<T>&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
template <class T>ostream &operator<<(ostream &o, const vector<T>&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;}
template <class T, class U>ostream &operator<<(ostream &o, const pair<T, U>&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;}
template <template <class tmp>  class T, class U> ostream &operator<<(ostream &o, const T<U> &obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr)o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;}
void print(void) {cout << endl;}
template <class Head> void print(Head&& head) {cout << head;print();}
template <class Head, class... Tail> void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward<Tail>(tail)...);}
template <class T> void chmax(T& a, const T b){a=max<T>(a,b);}
template <class T> void chmin(T& a, const T b){a=min<T>(a,b);}
void YN(bool flg) {cout << ((flg) ? "YES" : "NO") << endl;}
void Yn(bool flg) {cout << ((flg) ? "Yes" : "No") << endl;}
void yn(bool flg) {cout << ((flg) ? "yes" : "no") << endl;}


//Union Find Tree
class Union_Find_Tree_Size {
public:
	vector<int> parent;

    Union_Find_Tree_Size(int N = 1) : parent(N,-1){
	}
 
	int root(int n) {
        return (parent[n]<0?n:parent[n] = root(parent[n]));
	}

    bool same(int n, int m) {
		return root(n) == root(m);
	}
 
	void unite(int n, int m) {
		n = root(n);
		m = root(m);
		if (n == m) return;
		if(parent[n]>parent[m]) swap(n, m);
        parent[n] += parent[m];
        parent[m] = n;
	}

    int size(int n){
        return (-parent[root(n)]);
    }
};

int main() {
	int N; cin >> N;
	V<int> x(N),y(N);
	for(int i = 0; i < N; ++i) cin >> x[i] >> y[i];
	int M = 100000 + 1;
	V<V<int>> s(M),t(M);
	for(int i = 0; i < N; ++i){
		s[x[i]].push_back(i);
		t[y[i]].push_back(i);
	}
	Union_Find_Tree_Size uf(N);
	for(int i = 0; i < M; ++i){
		for(int j = 0; j + 1 < s[i].size(); ++j){
			uf.unite(s[i][j],s[i][j+1]);
		}
		for(int j = 0; j + 1 < t[i].size(); ++j){
			uf.unite(t[i][j],t[i][j+1]);
		}
	}
	V<set<int>> a(N),b(N);
	for(int i = 0; i < N; ++i){
		a[uf.root(i)].insert(x[i]);
		b[uf.root(i)].insert(y[i]);
	}
	ll ans = 0;
	for(int i = 0; i < N; ++i){
		ll l = a[i].size();
		ll r = b[i].size();
		ll c = uf.size(i);
		if(l*r>0)ans += (l*r)-c;
	}
	cout << ans << endl;

	
	return 0;
}


Measured memory_bytes: 23296