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

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

struct Int
  def prime_factor : Array(Tuple(self, Int32))
    result = Array(Tuple(self, Int32)).new
    n = self
    typeof(self).new(2).upto(Math.sqrt(self).ceil) do |x|
      count = 0
      while n % x == 0
        n //= x
        count += 1
      end
      result << {x, count} if count > 0
    end
    result << {n, 1} if n != 1
    result
  end

  def divisors : Array(self)
    result = Array(self).new
    typeof(self).new(1).upto(self) do |x|
      break if x * x > self
      result << x if self % x == 0
    end
    (0...result.size).reverse_each do |i|
      result << self // result[i] if result[i] * result[i] < self
    end
    result
  end
end

n = read_line.to_i64
ans = n + 1
(2i64..Math.sqrt(n).to_i64).each do |r|
  val = 1i64
  while val <= n
    ans = {ans, r}.min if n % val == 0 && n // val < r
    val = val * r + 1
  end
end

n.divisors.each do |a|
  b = n // a - 1
  ans = {ans, b}.min if a < b
end

puts ans