"""simple docstring"""


import sys

UpperCAmelCase__			=    (
    """73167176531330624919225119674426574742355349194934"""
    """96983520312774506326239578318016984801869478851843"""
    """85861560789112949495459501737958331952853208805511"""
    """12540698747158523863050715693290963295227443043557"""
    """66896648950445244523161731856403098711121722383113"""
    """62229893423380308135336276614282806444486645238749"""
    """30358907296290491560440772390713810515859307960866"""
    """70172427121883998797908792274921901699720888093776"""
    """65727333001053367881220235421809751254540594752243"""
    """52584907711670556013604839586446706324415722155397"""
    """53697817977846174064955149290862569321978468622482"""
    """83972241375657056057490261407972968652414535100474"""
    """82166370484403199890008895243450658541227588666881"""
    """16427171479924442928230863465674813919123162824586"""
    """17866458359124566529476545682848912883142607690042"""
    """24219022671055626321111109370544217506941658960408"""
    """07198403850962455444362981230987879927244284909188"""
    """84580156166097919133875499200524063689912560717606"""
    """05886116467109405077541002256983155200055935729725"""
    """71636269561882670428252483600823257530420752963450"""
)






def      __UpperCAmelCase       (      lowercase		):







  """simple docstring"""
  _UpperCAmelCase    			=   1
  for digit in s:
    product *= int(lowercase		)
  return product






def      __UpperCAmelCase       (      lowercase = N		):







  """simple docstring"""
  _UpperCAmelCase    			=   -sys.maxsize - 1
  _UpperCAmelCase    			=   n[:13]
  _UpperCAmelCase    			=   13
  while cur_index < len(lowercase		) - 13:
    if int(n[cur_index]		) >= int(substr[0]		):
      _UpperCAmelCase    			=   substr[1:] + n[cur_index]
      cur_index += 1
    else:
      _UpperCAmelCase    			=   max(lowercase ,str_eval(lowercase		)		)
      _UpperCAmelCase    			=   n[cur_index : cur_index + 13]
      cur_index += 13
  return largest_product


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

"""simple docstring"""


from collections.abc import Generator






def      __UpperCAmelCase       (      ):







  """simple docstring"""
  _UpperCAmelCase			,					_UpperCAmelCase    			=   0, 1
  while True:
    _UpperCAmelCase			,					_UpperCAmelCase    			=   b, a + b
    yield b






def      __UpperCAmelCase       (      lowercase = 10_00		):







  """simple docstring"""
  _UpperCAmelCase    			=   1
  _UpperCAmelCase    			=   fibonacci_generator()
  while len(str(next(lowercase		)		)		) < n:
    answer += 1
  return answer + 1


if __name__ == "__main__":
    print(solution(int(str(input()).strip())))
