# -*- coding: utf-8 -*-
# http://odz.sakura.ne.jp/projecteuler/index.php?cmd=read&page=Problem%2055
#
# そのまま..
# palindromic_number?は004.rbより．

def palindromic_number?(a)
  k = (Math.log(a) / Math.log(10)).to_i + 1
  if (k == 1)
    true
  else
    a = (0 ... k).map{|i| (a / 10 ** i).to_i % 10 }
    (0 ... (k / 2).to_i).reduce(true) do |t, i|
      t && (a[k - i - 1] == a[i])
    end
  end
end

puts (1 ... 10000).reduce(0) {|count, i|
  x = i + i.to_s.reverse.to_i
  count +
  (50.times.reduce(false){|ret|
    if (ret)
      ret
    else
      if (palindromic_number?(x))
        true
      else
        x = x + x.to_s.reverse.to_i
        false
      end
    end
  } ? 0 : 1)
}