#include <iostream>
#include <map>
#include <set>
#include <cmath>
#include <algorithm>
#include <vector>
#include <string>
#include <fstream>
#include <bitset>
#include <queue>
#include <stack>
#include <deque>
#include <time.h>

using std::cin;
using std::cout;
using std::cerr;
using std::endl;

using std::map;
using std::set;
using std::bitset;
using std::vector;
using std::string;
using std::multimap;
using std::multiset;
using std::deque;
using std::queue;
using std::stack;
using std::pair;
using std::iterator;

using std::sort;
using std::stable_sort;
using std::reverse;
using std::max_element;
using std::min_element;
using std::unique;
using std::ios_base;
using std::swap;
using std::min;
using std::max;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef string S;

namespace MySpace{
    struct Small_Segment_Tree{
        vector<int> a;
        int l, r;

        private:
        int __summ(int L, int R, int l, int r, int v)
        {
            if (L <= l && r <= R)
                return a[v];
            if (R <= l || r <= L)
                return 0;
            int m = (l + r) / 2;
            return __summ(L, R, l, m, 2 * v + 1) + __summ(L, R, m, r, 2 * v + 2);
        }

        void __set(int P, int l, int r, int v, int V)
        {
            if (l + 1 == r)
            {
                a[v] = V;
                return;
            }
            int m = (l + r) / 2;
            if (P < m)
            {
                __set(P, l, m, 2 * v + 1, V);
                a[v] = a[2 * v + 1] + a[2 * v + 2];
            }
            else
            {
                __set(P, m, r, 2 * v + 2, V);
                a[v] = a[2 * v + 1] + a[2 * v + 2];
            }
        }

        public:
        int Summ(int L, int R)
        {
            if (R < L)
                return 0;
            return __summ(L, R + 1, l, r, 0);
        }

        void Set(int P, int V)
        {
            __set(P, l, r, 0, V);
        }

        Small_Segment_Tree(int _n)
        {
            a.resize(4 * _n);
            l = 0, r = _n;
        }
    };
};

using std::__gcd;
using std::abs;
using namespace MySpace;

#define F(i, n) for (int (i) = 0; (i) != (n); (i)++)
#define fi first
#define se second
#define re return
#define all(x) (x).begin(), (x).end()
const ll MOD = 1e9 + 7;


ll n, k;
ll X, Y;
vector<int> FromX[2000000];
vector<int> FromY[2000000];
ll vis[2000000];
ll visY[2000000];

void dfsY(int v);

void dfsX(int v)
{
    if (vis[v] == 1)
        return;
    X++;
    vis[v] = 1;
    for (int i = 0; i < FromX[v].size(); i++)
    {
        dfsY(FromX[v][i]);
    }
}

void dfsY(int v)
{
    if (visY[v] == 1)
        return;
    Y++;
    visY[v]++;
    for (int i = 0; i < FromY[v].size(); i++)
    {
        dfsX(FromY[v][i]);
    }
}

signed main()
{
    srand(time(NULL));
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    ll n, k;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        int x, y;
        cin >> x >> y;
        FromX[x].push_back(y);
        FromY[y].push_back(x);
    }
    ll ans = 0;
    for (int i = 0; i <= 1000000; i++)
    {
        if (!vis[i])
        {
            X = 0, Y = 0;
            dfsX(i);
            ans += X * Y;
        }
    }
    cout << ans - n;
}


Measured memory_bytes: 110592