import javax.print.attribute.standard.MediaSize.Other
import scala.collection.mutable
import scala.collection.mutable.ArrayBuffer
import scala.io.StdIn.*
import scala.util.chaining.*
import scala.math.*
import scala.util.*

object ModInt:
  opaque type ModInt = Long
  inline def zero: ModInt = 0
  inline def one: ModInt = 1
  extension (value: Long)
    inline def asModInt(using inline mod: Int): ModInt =  value % mod
  extension (value: Int)
    inline def asModInt(using inline mod: Int): ModInt = value % mod
  trait Converter[T]:
    inline def convert(value: T)(using inline mod: Int): ModInt
  inline given Converter[Int] with
    override inline def convert(value: Int)(using inline mod: Int) = value.asModInt
  inline given Converter[Long] with
    override inline def convert(value: Long)(using inline mod: Int) = value.asModInt
  inline given Converter[ModInt] with
    override inline def convert(value: ModInt)(using inline mod: Int) = value
  extension (modInt: ModInt)
    inline def asLong(using inline mod: Int): Long = (modInt + mod) % mod
    inline def inverse(using inline mod: Int): ModInt =
      var x = modInt
      var y = mod.toLong
      var a = 1L
      var b = 0L
      var c = 0L
      var d = 1L
      while y != 0 do
        val q = x / y
        val e = a - c * q
        val f = b - d * q
        a = c
        b = d
        c = e
        d = f
        x = y
        y = c * modInt + d * mod
      require(x.abs == 1L)
      if x == 1 then a % mod else -a % mod
    inline def powMod(exp: Long)(using inline mod: Int): ModInt =
      var result = 1L
      var base = modInt
      var e = exp
      while e > 0 do
        if (e & 1) == 1 then
          result = result * base % mod
        base = base * base % mod
        e >>= 1
      result
    inline def powMod(exp: Int)(using inline mod: Int): ModInt = powMod(exp.toLong)
    inline def equals(other: ModInt)(using inline mod: Int): Boolean = modInt.asLong == other.asLong
  extension [L: Converter, R: Converter] (left: L)
    inline def +(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) + summon[Converter[R]].convert(right)).asModInt
    inline def -(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) - summon[Converter[R]].convert(right)).asModInt
    inline def *(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) * summon[Converter[R]].convert(right)).asModInt
    inline def /(right: R)(using inline mod: Int): ModInt = (summon[Converter[L]].convert(left) * summon[Converter[R]].convert(right).inverse).asModInt

@main def main =
  import ModInt._
  inline given MOD: Int = 998244353
  val Array(n, k) = readLine.split(' ').map(_.toInt)
  if k == 0 || k == n then
    println(1)
  else if k == 1 then
    println(if n % 2 == 0 then 2 else n - 2)
  else
    val factorial = Array.fill(n + 1){ModInt.one}
    for i <- 1 to n do
      factorial(i) = i * factorial(i - 1)
    val inverse = Array.fill(n + 1){ModInt.one}.tap(_(n) = factorial(n).inverse)
    for i <- n to 1 by -1 do
      inverse(i - 1) = i * inverse(i)
    def combination(n: Int, r: Int): ModInt = factorial(n) * inverse(r) * inverse(n - r)
    var result = ModInt.zero
    for end <- 0 to n - k by 2 do
      val pattern = combination(n - k - end + k - 2, k - 2) * (end + 1)
      result += pattern
    println(result.asLong)