/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author
 */

#include <iostream>
#include <fstream>

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

typedef long long ll;
#define tr(container, it) \
        for (auto it = container.begin(); it != container.end(); it++)
#define scontains(c, x) ((c).find(x) != (c).end())   //O(log n)
#define contains(c, x) (find((c).begin(),(c).end(),x) != (c).end()) //O(n)
#define pll pair<ll,ll>
#define pii pair<int,int>
#define mll map<ll,ll>
#define intv(x, a, b)((x)>=a && (x)<=b)
#define  rep(i, _begin, _end) for (__typeof(_end) end = _end, begin = _begin,  i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))
#define  _for(i, end) for (__typeof(end) i = 0, _len = (end); i < (_len); i += 1)
#define all(x) (x).begin(),(x).end()
#define SZ(x) ((ll)(x).size())
#define F first
#define S second
#define y0 y3487465
#define y1 y8687969
#define j0 j1347829
#define j1 j234892
#define next asdnext
#define prev asdprev
#define what_is(x) cerr << #x << " is " << x << endl;
#define error(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }
#define mod(x, m) ((((x) % (m)) + (m)) % (m))
#define bit(n) (1LL<<(n))
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );

const double PI = 2 * acos(.0);
const int INF = 0x3f3f3f3f;
const ll LLINF = 1000000000000000005LL;;
const ll MOD = (ll) (1e9) + 7;
void _mod(ll &x){x = mod(x, MOD);}
//const ll MOD = (ll) 998244353 ;
const double EPS = 1e-10;
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

template<typename A, size_t N, typename T>
void Fill(A (&array)[N], const T &val) {
    std::fill((T *) array, (T *) (array + N), val);
}


#define int ll

struct Point{
        int x,y,id;
    };

int N;
int X[101010], Y[101010];
map<int, vector<int>> XIDs, YIDs;
set<int> xpoints, ypoints;
int visited[101010];
Point Points[101010];
class FMustBeRectangular {
public:

void solve(std::istream& cin, std::ostream& cout) {
    int N;
    cin >> N;
    Fill(visited, 0);
    _for(i,N)cin >> Points[i].x >> Points[i].y, Points[i].id = i;
    _for(i,N)XIDs[Points[i].x].emplace_back(i), YIDs[Points[i].y].emplace_back(i);
    ll sum = 0;
    _for(i,N){
        if(!visited[i]){
            int del = 0;
            xpoints.clear(), ypoints.clear();
            queue<int> Q;
            Q.push(i), visited[i] = 1;
            while(!Q.empty()){
                int p = Q.front();
                int x = Points[p].x, y = Points[p].y;
                xpoints.insert(x), ypoints.insert(y);
                for(int id : XIDs[x])if(!visited[id])Q.push(id),visited[id] = 1;
                for(int id : YIDs[y])if(!visited[id])Q.push(id),visited[id] = 1;
                Q.pop();
                del ++;
            }
            sum += (ll)SZ(xpoints)*SZ(ypoints) - del;
        }
    }
    cout << sum << endl;




}
};


#undef int
int main() {
	FMustBeRectangular solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	in.tie(0); ios::sync_with_stdio(0); out<<fixed<<setprecision(20);
	solver.solve(in, out);
	return 0;
}


Measured memory_bytes: 20480