n = gets.chomp
k = gets.to_i
digit = n.length
dp = Array.new(digit+1).map{Array.new(2).map{Array.new(k+1,0)}}
dp[0][0][0] = 1
dp[0][1][0] = 0
zeronum = 0
1.upto(digit) do |i|
  (k+1).times do |j|
    if j == 0
      dp[i][0][j] = n[i-1] == "0" ? dp[i-1][0][j] : 0
      dp[i][1][j] = dp[i-1][1][j] + dp[i-1][0][j]
    else
      dp[i][0][j] = n[i-1] == "0" ? dp[i-1][0][j] : dp[i-1][0][j-1]
      dp[i][1][j] = dp[i-1][1][j-1] * 9 + dp[i-1][1][j] + dp[i-1][0][j-1] * (n[i-1].to_i - 1) + dp[i-1][0][j]
    end
  end
  zeronum += 1 if n[i-1] == "0"
end
p dp[digit][0][k] + dp[digit][1][k] - zeronum