fun C(a: Int, b: Int): Int {
  var r = 1
  for (i in (a - b + 1)..(a)) {
  	r *= i
  }
  
  for (i in 1..b) {
  	r /= i
  }
  
  return r
}

fun pow(a: Int, b: Int): Int {
	return Math.pow(a.toDouble(), b.toDouble()).toInt()
}

fun f(N_Str: String, K: Int): Int {
  if (K == 0) {
  	return 1
  }
  
  val M = N_Str.length
  var res = 0
  for (i in K..M - 1) {
  	res += C(i - 1, K - 1)
  }
  res *= pow(9, K)
  
  val a = N_Str.substring(0, 1).toInt()
  res += (a - 1) * pow(9, K - 1) * C(M - 1, K - 1) 
  
  for (i in 1..M - 1) {
  	if (N_Str[i] == '0') {
    	continue
    } 
   	return res + f(N_Str.substring(i), K - 1)
  }
  
  return res + 1
}

fun main(args: Array<String>) {
  val N_Str = readLine()!!
  val K = readLine()!!.toInt()
  
  println(f(N_Str, K))
}