x,y,h = gets.split.map(&:to_i)
xy = [x,y].map{|v| v.to_f * 1000 }.sort
ans = 40.times.find do |n|
  if xy[1] <= h
    true
  else
    if xy[0] > h
      xy[0] /= 2
    else
      xy[1] /= 2
    end
    h *= 2
    false
  end
end
puts ans