#include <bits/stdc++.h>
using namespace std;
typedef long long   signed int LL;
typedef long long unsigned int LU;
#define incID(i, l, r) for(LL i = (l)    ; i <  (r); ++i)
#define incII(i, l, r) for(LL i = (l)    ; i <= (r); ++i)
#define decID(i, l, r) for(LL i = (r) - 1; i >= (l); --i)
#define decII(i, l, r) for(LL i = (r)    ; i >= (l); --i)
#define inc(i, n)  incID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec(i, n)  decID(i, 0, n)
#define dec1(i, n) decII(i, 1, n)
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))
#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define  ALL(v)  v.begin(),  v.end()
#define RALL(v) v.rbegin(), v.rend()
template<typename T> bool setmin  (T & a, T b) { if(b <  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmax  (T & a, T b) { if(b >  a) { a = b; return true; } else { return false; } }
template<typename T> bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } }
template<typename T> bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } }
LL mo(LL a, LL b) { assert(b > 0); a %= b; if(a < 0) { a += b; } return a; }
LL fl(LL a, LL b) { assert(b > 0); return (a > 0 ? a / b : (a - b + 1) / b); }
LL ce(LL a, LL b) { assert(b > 0); return (a < 0 ? a / b : (a + b - 1) / b); }
template<typename T> T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define bit(b, i) (((b) >> (i)) & 1)
#define BC __builtin_popcountll
#define SC static_cast
#define SI(v) SC<int>(v.size())
#define SL(v) SC<LL >(v.size())
#define RF(e, v) for(auto & e: v)
#define ef else if
#define UR assert(false)

// ---- ----

class UnionFind {
private:
	int n, s;
	vector<int> t;
	vector<vector<int>> v;
public:
	UnionFind(int arg_n = 0) { init(arg_n); }
	void init(int arg_n) {
		n = s = arg_n;
		t.clear();
		v.clear();
		inc(i, n) { t.PB(i); v.EB(1, i); }
	}
	int get_n() { return n; }
	int size() { return s; }
	int id(int x) { return t.at(x); }
	const vector<vector<int>> & get_v() { return v; }
	bool unite(int x, int y) {
		x = id(x);
		y = id(y);
		if(x == y) { return false; }
		if(v[x].size() < v[y].size()) { swap(x, y); }
		for(auto & e: v[y]) { v[x].PB(e); t[e] = x; }
		v[y].clear();
		s--;
		return true;
	}
	bool same(int x, int y) { return (id(x) == id(y)); }
	const vector<int> & operator[](int x) { return v[id(x)]; }
	friend ostream & operator<<(ostream & os, const UnionFind & uf) {
		inc(i, uf.n) { os << i << ": "; for(auto & e: uf.v[i]) { os << e << " "; } os << "\n"; }
		return os;
	}
};

// ---- ----

int n, x[100000], y[100000];
map<int, vector<int>> mx, my;

int main() {
	cin >> n;
	inc(i, n) { cin >> x[i] >> y[i]; }
	
	inc(i, n) {
		mx[x[i]].PB(i);
		my[y[i]].PB(i);
	}
	
	UnionFind uf(n);
	RF(e, mx) { inc(i, SI(e.SE) - 1) { uf.unite(e.SE[i], e.SE[i + 1]); } }
	RF(e, my) { inc(i, SI(e.SE) - 1) { uf.unite(e.SE[i], e.SE[i + 1]); } }
	
	LL ans = -n;
	inc(i, n) {
		set<int> sx, sy;
		RF(e, uf.get_v()[i]) {
			sx.insert(x[e]);
			sy.insert(y[e]);
		}
		ans += SL(sx) * SL(sy);
	}
	
	cout << ans << endl;
	
	return 0;
}


Measured memory_bytes: 25776