object Main {
  import java.io.{BufferedReader, InputStream, InputStreamReader}
  import java.util.StringTokenizer
  import scala.reflect.ClassTag

  def main(args: Array[String]): Unit = {
    val out = new java.io.PrintWriter(System.out)
    new Main(out, new InputReader(System.in)).solve()
    out.flush()
  }

  private val oj = System.getenv("ATCODER_DEBUG") == null
  def DEBUG(f: => Unit): Unit = {
    if (!oj){ f }
  }
  def debug(as: Array[Boolean]): Unit = if (!oj){ debug(as.map(x => if(x) "1" else "0").mkString) }
  def debug(as: Array[Int]): Unit = if (!oj){ debug(as.mkString(" ")) }
  def debug(as: Array[Long]): Unit =if (!oj){ debug(as.mkString(" ")) }
  def debugDim(m: Array[Array[Int]]): Unit = if (!oj){
    REP(m.length) { i =>
      debug(m(i))
    }
  }
  def debugDimFlip(m: Array[Array[Long]]): Unit = if (!oj){
    REP(m(0).length) { j =>
      REP(m.length) { i =>
        System.err.print(m(i)(j))
        System.err.print(" ")
      }
      System.err.println()
    }
  }
  def debug(s: => String): Unit = DEBUG {
    System.err.println(s)
  }
  def debugL(num: => Long): Unit = DEBUG {
    System.err.println(num)
  }

  class InputReader(val stream: InputStream) {
    private val reader = new BufferedReader(new InputStreamReader(stream), 32768)
    private var tokenizer: StringTokenizer = _

    def next(): String = {
      while (tokenizer == null || !tokenizer.hasMoreTokens)
        tokenizer = new StringTokenizer(reader.readLine)
      tokenizer.nextToken
    }

    def nextInt(): Int = Integer.parseInt(next())
    def nextLong(): Long = java.lang.Long.parseLong(next())
    def nextChar(): Char = next().charAt(0)

    def ni(): Int = nextInt()
    def nl(): Long = nextLong()
    def nc(): Char = nextChar()
    def ns(): String = next()
    def ns(n: Int): Array[Char] = ns().toCharArray
    def na(n: Int, offset: Int = 0): Array[Int] = map(n)(_ => ni() + offset)
    def na2(n: Int, offset: Int = 0): (Array[Int], Array[Int]) = {
      val A1, A2 = Array.ofDim[Int](n)
      REP(n) { i =>
        A1(i) = ni() + offset
        A2(i) = ni() + offset
      }
      (A1, A2)
    }
    def nm(n: Int, m: Int): Array[Array[Int]] = {
      val A = Array.ofDim[Int](n, m)
      REP(n) { i =>
        REP(m) { j =>
          A(i)(j) = ni()
        }
      }
      A
    }
    def nal(n: Int): Array[Long] = map(n)(_ => nl())
    def nm_c(n: Int, m: Int): Array[Array[Char]] = map(n) (_ => ns(m))
  }

  def REP(n: Int, offset: Int = 0)(f: Int => Unit): Unit = {
    var i = offset
    val N = n + offset
    while(i < N) { f(i); i += 1 }
  }
  def REP_r(n: Int, offset: Int = 0)(f: Int => Unit): Unit = {
    var i = n - 1 + offset
    while(i >= offset) { f(i); i -= 1 }
  }
  def TO(from: Int, to: Int)(f: Int => Unit): Unit = {
    REP(to - from + 1, from) { i =>
      f(i)
    }
  }
  def map[@specialized A: ClassTag](n: Int, offset: Int = 0)(f: Int => A): Array[A] = {
    val res = Array.ofDim[A](n)
    REP(n)(i => res(i) = f(i + offset))
    res
  }

  def sumL(as: Array[Int]): Long = {
    var s = 0L
    REP(as.length)(i => s += as(i))
    s
  }
  def cumSum(as: Array[Int]): Array[Long] = {
    val cum = Array.ofDim[Long](as.length + 1)
    REP(as.length) { i =>
      cum(i + 1) = cum(i) + as(i)
    }
    cum
  }
}

class Main(out: java.io.PrintWriter, sc: Main.InputReader) {
  import sc._
  import Main._
  import java.util.Arrays.sort

  import scala.collection.mutable
  import math.{abs, max, min}
  import mutable.ArrayBuffer

  // toIntとか+7とかするならvalにしろ
  @inline private def MOD = 1000000007

  def solve(): Unit = {
    val N = ni()
    val MAX = 1e5.toInt
    val uf = new UnionFind(MAX)
    val XsbyY = Array.fill[ArrayBuffer[Int]](MAX)(ArrayBuffer())
    val P = Array.ofDim[(Int, Int)](N)
    REP(N) { i =>
      val x, y = ni() - 1
      uf.addY(x, y)
      XsbyY(y) += x
      P(i) = (x, y)
    }

    REP(XsbyY.length) { i =>
      val xs = XsbyY(i)
      REP(xs.length - 1) { j =>
        uf.unite(xs(j), xs(j + 1))
      }
    }

    var ans = 0L
    val used = Array.ofDim[Boolean](MAX)
    REP(N) { i =>
      val x = P(i)._1
      val id = uf.find(x)
      if (!used(id)) {
        ans += uf.cntNodes(id)
        used(id) = true
      }
    }
    ans -= N
    out.println(ans)
  }

class UnionFind(val n: Int) {
  private val par = Array.ofDim[Int](n)
  REP(n) (i => par(i) = i)
  val ys: Array[mutable.Set[Int]] = Array.fill[mutable.Set[Int]](n)(mutable.Set())
  val xs: Array[mutable.Set[Int]] = Array.tabulate[mutable.Set[Int]](n) { x =>
    val set = mutable.Set[Int]()
    set += x
    set
  }
  private val visits = Array.ofDim[Int](n) // 訪れた場所をfind毎に用意するのがもったいないのでつかいまわす

  def find(x: Int): Int = {
    var ptr = 0
    def step(x: Int): Int = {
      if (par(x) == x) x
      else {
        visits(ptr) = x
        ptr += 1
        step(par(x))
      }
    }

    val res = step(x)
    REP(ptr){ i => par(visits(i)) = res }
    res
  }

  private def merge(node: Int, rt: Int): Int = {
    par(node) = rt
    ys(rt) ++= ys(node)
    xs(rt) ++= xs(node)
    rt
  }

  def unite(x1: Int, x2: Int): Int = {
    val id1 = find(x1)
    val id2 = find(x2)
    if (id1 == id2) id1
    else {
      if (ys(id1).size < ys(id2).size)
        merge(id1, id2)
      else
        merge(id2, id1)
    }
  }

  def addY(x: Int, y: Int): Unit = {
    ys(find(x)) += y
  }

  def cntNodes(id: Int): Long = {
    ys(id).size.toLong * xs(id).size
  }
}
}

Measured memory_bytes: 131192