using System;
using System.IO;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using E = System.Linq.Enumerable;

partial class Solver
{
    class Point
    {
        public int Id, X, Y;
    }

    public void Run()
    {
        var N = ni();
        var x = new int[N];
        var y = new int[N];
        for (int i = 0; i < N; i++)
        {
            x[i] = ni();
            y[i] = ni();
        }
        var points = E.Range(0, N)
            .Select(i => new Point { Id = i, X = x[i], Y = y[i] })
            .ToArray();

        var pointsByX = points.ToLookup(p => p.X);
        var pointsByY = points.ToLookup(p => p.Y);

        var d = new DisjointSet(N);
        foreach (var kv in pointsByX)
        {
            var v = kv.ToArray();
            for (int i = 0; i < v.Length - 1; i++)
            {
                d.Unite(v[i].Id, v[i + 1].Id);
            }
        }
        foreach (var kv in pointsByY)
        {
            var v = kv.ToArray();
            for (int i = 0; i < v.Length - 1; i++)
            {
                d.Unite(v[i].Id, v[i + 1].Id);
            }
        }
        var pointsByGroup = points.ToLookup(p => d.Root(p.Id));
        long ans = 0;
        foreach (var kv in pointsByGroup)
        {
            var xN = kv.Select(p => p.X).Distinct().Count();
            var yN = kv.Select(p => p.Y).Distinct().Count();
            ans += 1L * xN * yN;
            ans -= kv.Count();
        }
        cout.WriteLine(ans);
    }

}

public class DisjointSet
{
    private int[] group;
    public int GroupCount { get; private set; }
    public DisjointSet(int n)
    {
        group = new int[n];
        Clear();
        GroupCount = n;
    }
    public bool Unite(int x, int y)
    {
        x = Root(x); y = Root(y);
        if (x == y) return false;
        if (group[y] < group[x]) return Unite(y, x);
        group[x] += group[y];
        group[y] = x;
        GroupCount--;
        return true;
    }
    public bool IsSameSet(int x, int y) { return Root(x) == Root(y); }
    public int Root(int x) { return group[x] < 0 ? x : group[x] = Root(group[x]); }
    public int Size(int x) { return -group[Root(x)]; }
    public void Clear()
    {
        for (int i = 0; i < group.Length; i++)
        {
            group[i] = -1;
        }
    }
};

// PREWRITEN CODE BEGINS FROM HERE
partial class Solver : Scanner
{
    public static void Main(string[] args)
    {
#if LOCAL
        new Solver(Console.In, Console.Out).Run();
#else
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        new Solver(Console.In, Console.Out).Run();
        Console.Out.Flush();
#endif
    }

#pragma warning disable IDE0052
    private readonly TextReader cin;
    private readonly TextWriter cout;
#pragma warning restore IDE0052

    public Solver(TextReader reader, TextWriter writer)
        : base(reader)
    {
        this.cin = reader;
        this.cout = writer;
    }
    public Solver(string input, TextWriter writer)
        : this(new StringReader(input), writer)
    {
    }

#pragma warning disable IDE1006
#pragma warning disable IDE0051
    private int ni() { return NextInt(); }
    private int[] ni(int n) { return NextIntArray(n); }
    private long nl() { return NextLong(); }
    private long[] nl(int n) { return NextLongArray(n); }
    private double nd() { return NextDouble(); }
    private double[] nd(int n) { return NextDoubleArray(n); }
    private string ns() { return Next(); }
    private string[] ns(int n) { return NextArray(n); }
#pragma warning restore IDE1006
#pragma warning restore IDE0051
}

public static class LinqPadExtension
{
    static public T Dump<T>(this T obj)
    {
#if LOCAL
        return LINQPad.Extensions.Dump(obj);
#else
        return obj;
#endif
    }
}
public class Scanner
{
    private readonly TextReader Reader;
    private readonly Queue<string> TokenQueue = new Queue<string>();
    private readonly CultureInfo ci = CultureInfo.InvariantCulture;

    public Scanner()
        : this(Console.In)
    {
    }

    public Scanner(TextReader reader)
    {
        this.Reader = reader;
    }

    public int NextInt() { return int.Parse(Next(), ci); }
    public long NextLong() { return long.Parse(Next(), ci); }
    public double NextDouble() { return double.Parse(Next(), ci); }
    public string[] NextArray(int size)
    {
        var array = new string[size];
        for (int i = 0; i < size; i++) array[i] = Next();
        return array;
    }
    public int[] NextIntArray(int size)
    {
        var array = new int[size];
        for (int i = 0; i < size; i++) array[i] = NextInt();
        return array;
    }

    public long[] NextLongArray(int size)
    {
        var array = new long[size];
        for (int i = 0; i < size; i++) array[i] = NextLong();
        return array;
    }

    public double[] NextDoubleArray(int size)
    {
        var array = new double[size];
        for (int i = 0; i < size; i++) array[i] = NextDouble();
        return array;
    }

    public string Next()
    {
        if (TokenQueue.Count == 0)
        {
            if (!StockTokens()) throw new InvalidOperationException();
        }
        return TokenQueue.Dequeue();
    }

    public bool HasNext()
    {
        if (TokenQueue.Count > 0)
            return true;
        return StockTokens();
    }
    static readonly char[] _separator = new[] { ' ' };
    private bool StockTokens()
    {
        while (true)
        {
            var line = Reader.ReadLine();
            if (line == null) return false;
            var tokens = line.Split(_separator, StringSplitOptions.RemoveEmptyEntries);
            if (tokens.Length == 0) continue;
            foreach (var token in tokens)
                TokenQueue.Enqueue(token);
            return true;
        }
    }
}


Measured memory_bytes: 44568