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
n.divisors.each do |d|
  if d <= Math.sqrt(n)
    (d + 1..n).each do |x|
      val = 1i64
      while val <= n // d
        ans = {ans, x}.min if n // d == val
        val = val * x + 1
      end
    end
  else
    d.divisors.each do |a|
      b = n // a - 1
      ans = {ans, b}.min if a < b
    end
  end
end
puts ans