lib C
  fun strtoll(s : UInt8*, p : UInt8**, b : Int32) : Int64
end

class String
  def to_i64
    C.strtoll(self, nil, 10)
  end
end

require "big"

def calc(n : BigInt, k : Int32)
  res = 0.to_big_i
  k.times do |i|
    return -1 if n == 0
    res += n
    n //= 2
  end
  return res
end

n = read_line.to_big_i
puts (1..64).reverse_each.map { |k|
  val = (1.to_big_i..n).bsearch { |first|
    calc(first, k) >= n
  }
  [val && calc(val, k) == n, val]
}.find { |v|
  v[0]
}.not_nil![1]