import scala.io.StdIn

object Solution {
  private final case class Pair(i1: Int, i2: Int)

  private def group(n: Int, pairs: Seq[Pair]): Seq[Seq[Int]] = {
    val parents = (0 to n).toArray

    def root(i: Int): Int = {
      if (parents(i) != i)
        parents(i) = root(parents(i))
      parents(i)
    }

    pairs.foreach { pair =>
      val root1 = root(pair.i1)
      val root2 = root(pair.i2)
      if (root1 < root2)
        parents(root2) = root1
      else if (root1 > root2)
        parents(root1) = root2
    }
    (1 to n).groupBy(root).values.toSeq
  }

  private def cost(n: Int): Int = {
    math.ceil(math.sqrt(n)).toInt
  }

  def main(args: Array[String]): Unit = {
    val arr = Iterator
      .continually(StdIn.readLine())
      .takeWhile(null != _)
      .map(_.trim)
    val n = arr.next().toInt
    val m = arr.next().toInt
    val pairs = (1 to m)
      .map(_ => arr.next().split(' ').map(_.toInt))
      .map(p => Pair(p.head, p.last))
    val groups = group(n, pairs)
    val costs = groups.map(_.length).map(cost)
    println(costs.sum)
  }
}