
'''simple docstring'''





def 							snake_case				(		UpperCAmelCase = 9_9_8_0_0_1						)->      int:







      """simple docstring"""
      __A													=      0
      for i in range(9_9_9   ,	9_9   ,	-1						):  # 3 digit numbers range from 999 down to 100
            for j in range(9_9_9   ,	9_9   ,	-1						):
                  __A													=      str(i * j						)
                  if product_string == product_string[::-1] and i * j < n:
                        __A													=      max(UpperCAmelCase   ,	i * j						)
      return answer


if __name__ == "__main__":
 print(f'''{solution() = }''')











"""simple docstring"""







from math import floor, sqrt


def  __SCREAMING_SNAKE_CASE (  __UpperCAmelCase      ):
		_lowercase				: Optional[int]     =   0.0
		_lowercase				: Dict     =   1.0
		_lowercase				: Optional[int]     =   int(sqrt(__UpperCAmelCase      )      )
		_lowercase				: Optional[Any]     =   root
		_lowercase				: Dict     =   0
		while integer_part != 2 * root:
				_lowercase				: str     =   denominator * integer_part - numerator
				_lowercase				: Optional[int]     =   (n - numerator**2) / denominator
				_lowercase				: List[str]     =   int((root + numerator) / denominator      )
				period += 1
		return period


def  __SCREAMING_SNAKE_CASE (  __UpperCAmelCase = 10000      ):
		_lowercase				: List[str]     =   0
		for i in range(2   ,				n + 1      ):
				_lowercase				: Dict     =   sqrt(__UpperCAmelCase      )
				if sr - floor(__UpperCAmelCase      ) != 0 and continuous_fraction_period(__UpperCAmelCase      ) % 2 == 1:
						count_odd_periods += 1
		return count_odd_periods


if __name__ == "__main__":
		print(F'{solution(int(input().strip()))}')



