import java.io._
import java.util.StringTokenizer
import scala.util.control.Breaks.{breakable,break}

object Main extends App {
  val in = new InputReader(System.in)
  val pw = new PrintWriter(System.out)

  val N, H = in.next().toInt
  val _a = new Array[Int](N)
  val _b = new Array[Int](N)

  for(i <- 0 until N) {
    val a, b = in.next().toInt
    _a(i) = a
    _b(i) = b
  }

  val a = _a.sorted.reverse
  val b = _b.filter(_ > a(0)).sorted.reverse

  var ans = 0
  var hp = H
  breakable {
    
    for (e <- b) {
      hp -= e
      ans += 1
      if(hp <= 0)
        break
    }
  }

  if(hp <= 0)
    println(ans)
  else {
    ans += hp / a(0)
    if (hp % a(0) != 0) {
      ans += 1
    }
    println(ans)
  }

}


class InputReader(stream: InputStream) {
  private val reader = new BufferedReader(new InputStreamReader(stream))
  private var tokenizer: StringTokenizer = new StringTokenizer(reader.readLine())
  def next(): String = {
    while (!tokenizer.hasMoreTokens()) {
      tokenizer = new StringTokenizer(reader.readLine())
    }
    tokenizer.nextToken()
  }
}
