import java.io.{BufferedReader, InputStream, InputStreamReader, PrintWriter}
import java.util.StringTokenizer

import scala.collection.mutable
import scala.util.Sorting
import math.{abs, max, min}
import scala.collection.mutable.{ArrayBuffer, ListBuffer}
import scala.reflect.ClassTag

object Main {
  val MOD = 1000000007
  val out = new PrintWriter(System.out)
  def solve(): Unit = {
    val sc = new InputReader(System.in)
    val N = sc.nextInt()
    val A = map(N)(_ => sc.nextInt())
    val ans = A.grpBy(identity).sumBy { case (num, as) =>
      val cnt = as.length
      if (cnt >= num) cnt - num
      else cnt
    }

    out.println(ans)
  }


  def main(args: Array[String]): Unit = {
    solve()
    out.flush()
  }


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

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

    def nextInt(): Int = next.toInt
    def nextLong(): Long = next.toLong
    def nextChar(): Char = next.charAt(0)
  }

  private def rep(n: Int)(f: Int => Unit): Unit = {
    var i = 0
    while(i < n) {
      f(i)
      i += 1
    }
  }

  private def map[@specialized A: ClassTag](n: Int)(f: Int => A): Array[A] = {
    val res = Array.ofDim[A](n)
    var i = 0
    while(i < n) {
      res(i) = f(i)
      i += 1
    }
    res
  }

  private implicit class ArrayOpts[A](val as: Array[A]) extends AnyVal {
    def maxByOpt[B: Ordering](f: A => B): Option[A] = {
      if (as.nonEmpty) Some(as.maxBy(f)) else None
    }

    def grpBy[K](f: A => K): mutable.Map[K, ArrayBuffer[A]] = {
      val map = mutable.Map.empty[K, ArrayBuffer[A]]
      as.rep { a =>
        val k = f(a)
        map.getOrElseUpdate(k, ArrayBuffer()) += a
      }
      map
    }

    def rep[@specialized B](f: A => B): Unit = {
      var i = 0
      val N = as.length
      while(i < N) {
        f(as(i))
        i += 1
      }
    }
  }

  private implicit class IterableOpts[A](val as: Iterable[A]) extends AnyVal {
    def sumBy[B](f: A => B)(implicit num: Numeric[B]): B = {
      as.foldLeft(num.zero)((acc, a) => num.plus(acc, f(a)))
    }
  }
}
