#include <bits/stdc++.h>
using namespace std;
#define Rep(i,n) for(int i=0;i<(int)(n);i++)
#define For(i,n1,n2) for(int i=(int)(n1);i<(int)(n2);i++)
#define REP(i,n) for(ll i=0;i<(ll)(n);i++)
#define RREP(i,n) for(ll i=((ll)(n)-1);i>=0;i--)
#define FOR(i,n1,n2) for(ll i=(ll)(n1);i<(ll)(n2);i++)
#define RFOR(i,n1,n2) for(ll i=((ll)(n1)-1);i>=(ll)(n2);i--)
#define all(a)  (a).begin(),(a).end()
#define SORT(a) sort((a).begin(),(a).end())
#define oorret 0
#define oor(x) [&](){try{x;} catch(const out_of_range& oor){return oorret;} return x;}()
#define IOS cin.tie(0),ios::sync_with_stdio(false)
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll, ll> P;
template<typename T1, typename T2> inline bool chmin(T1& a, T2 b) { if (a > b) { a = b; return 1; }return 0; }
template<typename T1, typename T2> inline bool chmax(T1& a, T2 b) { if (a < b) { a = b; return 1; }return 0; }
template<class Type>struct is_vector : std::false_type {};
template<class ValueType, class Alloc>struct is_vector<std::vector<ValueType, Alloc>> : std::true_type {};
template <typename T> inline ostream& operator << (ostream& out, const vector<T>& v) {
	if (v.empty())return out;
	constexpr bool is_vector_v = is_vector<T>::value;
	if (is_vector_v)for (auto itr = v.begin(); itr != v.end();)out << (*itr), out << ((++itr != v.end()) ? "\n" : "");
	else for (auto itr = v.begin(); itr != v.end();)out << (*itr), out << ((++itr != v.end()) ? " " : "");
	return out;
}
inline void put() {}
template<class T> inline void put(const T& first) { std::cout << first << "\n"; }
template<class T, class... N> inline void put(const T& first, const N& ... rest) { std::cout << first << " "; put(rest...); }
inline void putn() {}
template<class T, class... N> inline void putn(const T& first, const N& ... rest) { std::cout << first << "\n"; putn(rest...); }

class UnionFind {
private:
	vector<int> par, height, size;
	int ele;
public:
	UnionFind(int n) {
		par.resize(n);
		REP(i, n) {
			par[i] = i;
		}
		height.resize(n, 0);
		size.resize(n, 1);
		ele = n;
	}
	int root(int x) {
		if (par[x] == x) {
			return x;
		} else {
			par[x] = root(par[x]);
			return par[x];
		}
	}
	bool same(int x, int y) {
		return root(x) == root(y);
	}
	void unite(int x, int y) {
		x = root(x);
		y = root(y);
		if (x == y)return;
		ele--;
		if (height[x] < height[y]) {
			par[x] = y;
			size[y] += size[x];
		} else {
			par[y] = x;
			size[x] += size[y];
			if (height[x] == height[y])height[x]++;
		}
	}
	int get_size(int x) {
		x = root(x);
		return size[x];
	}
	int get_ele() {
		return ele;
	}
};

int main() {
	IOS;
	int n;
	cin >> n;
	vector<int> x(n), y(n);
	set<int> sx, sy;
	REP(i, n) {
		cin >> x[i] >> y[i];
		sx.insert(x[i]);
		sy.insert(y[i]);
	}
	int m = 1e5 + 1;
	vector<int> tx(m, -1), ty(m, -1);
	int cnt = 0;
	for (auto v : sx) {
		tx[v] = cnt++;
	}
	cnt = n;
	for (auto v : sy) {
		ty[v] = cnt++;
	}
	UnionFind ufx(n), ufy(n),ufz(n*2);
	vector<vector<int>> path(n*2);
	REP(i, n) {
		int t1 = tx[x[i]];
		int t2 = ty[y[i]];
		//ufz.unite(t1, t2);
		path[t1].push_back(t2);
		path[t2].push_back(t1);
	}
	REP(i, n) {
		int l = (int)path[i].size();
		REP(j, l - 1) {
			int ny1 = path[i][j]-n;
			int ny2 = path[i][j + 1]-n;
			ufy.unite(ny1, ny2);
		}
	}
	REP(i, n) {
		int l = (int)path[i + n].size();
		REP(j, l - 1) {
			int nx1 = path[i + n][j];
			int nx2 = path[i + n][j + 1];
			ufx.unite(nx1, nx2);
		}
	}
	ll res = 0;
	vector<int> ux(n, 0);
	REP(i, n) {
		int r = ufx.root(i);
		if (!ux[r]) {
			ux[r] = 1;
			int tx = ufx.get_size(r);
			int ty = 0;
			if (path[i].size()) {
				ty = ufy.get_size(path[i][0] - n);
			}
			res += (ll)tx * ty;
		}
	}
	put(res-n);
	return 0;
}


Measured memory_bytes: 19456