#include <bits/stdc++.h>
#include <random>

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
#define int ll
//#define int __int128
//#define ll __int128
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector< vi > vvi;
typedef vector< vvi > vvvi;
typedef vector<short> vs;
typedef vector<vs> vvs;
typedef vector<vvs> vvvs;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<vvl> vvvl;
typedef vector<ld> vld;
typedef vector<vld> vvld;
typedef vector<vvld> vvvld;
typedef vector<string> vst;
typedef vector<vst> vvst;
typedef pair<ld, ld> pld;
typedef complex<double> base;

#define inmin(a, b) a = min(a, (b))
#define inmax(a, b) a = max(a, (b))
#define ALL(a) a.begin(),a.end()
#define RALL(a) a.rbegin(),a.rend()
#define sqr(x) ((x) * (x))
#define fori(i, n) for(int i = 0; i < int(n); ++i)
#define SZ(a) ((int)((a).size()))
#define triple(T) tuple<T, T, T>
#define quad(T) tuple<T, T, T, T>
#define watch(x) cerr << (#x) << " = " << (x) << endl;

const double PI = 2 * acos(0.0);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng_64(chrono::steady_clock::now().time_since_epoch().count());

const string DIGITS = "0123456789";
const string ALPH = "abcdefghijklmnopqrstuvwxyz";

template <class T0, class T1>
inline ostream & operator << (ostream &out, pair<T0, T1> &a) {
    return out << "{" << a.first << ", " << a.second << "}";
}

template <class T0, class T1, class T2>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << "}";
}

template <class T0, class T1, class T2, class T3>
inline ostream & operator << (ostream &out, tuple<T0, T1, T2, T3> &a) {
    return out << "{" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << ", " <<  get<3>(a) << "}";
}

template<class T>
inline ostream & operator << (ostream &out, vector<T> &a) {
    out << "[";
    fori (i, a.size())
        out << a[i] << vector<string>{", ", "]  "}[i + 1 == a.size()];
    return out;
}

void smain();

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

#ifdef RUS_HOME
    freopen("input.txt", "r", stdin);
    clock_t start = clock();
#endif
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    cout << setprecision(12) << fixed;
    smain();
#ifdef RUS_HOME
    cout << "\n\nTOTAL EXECUTION TIME: " << float( clock () - start ) /  CLOCKS_PER_SEC << endl;
#endif
}
const int oo = 1e9;
const int N = 1e5 + 100;
int MOD = 1e9 + 7;

vi gx[N], gy[N];
vi cur(N);
vi p[N];

void uni(int a, int b) {
    a = cur[a];
    b = cur[b];
    if (a == b)
        return;
    if (p[a].size() > p[b].size())
        swap(a, b);
    for (int i = 0; i < p[a].size(); i++) {
        p[b].push_back(p[a][i]);
        cur[p[a][i]] = b;
    }
    p[a].clear();
}

void smain() {

    int n; cin >> n;
    vi x(n), y(n);
    for (int i = 0; i < n; i++) {
        cin >> x[i] >> y[i];
        gx[x[i]].push_back(i);
        gy[y[i]].push_back(i);
        cur[i] = i;
        p[i].push_back(i);
    }

    for (int i = 0; i < N; i++) {
        for (int j = 1; j < gx[i].size(); j++) {
            uni(gx[i][j], gx[i][j - 1]);
        }
        for (int j = 1; j < gy[i].size(); j++) {
            uni(gy[i][j], gy[i][j - 1]);
        }
    }
    int ans = 0;
    for (int i = 0; i < N; i++) {
        set <int> sx, sy;
        for (int j = 0; j < p[i].size(); j++) {
            sx.insert(x[p[i][j]]);
            sy.insert(y[p[i][j]]);
        }
        ans += sx.size() * sy.size();
    }
    cout << ans - n;







}

Measured memory_bytes: 26736