



def      __lowercase(						UpperCAmelCase__			):


      """simple docstring"""



      if n == 1 or not isinstance(UpperCAmelCase__ , UpperCAmelCase__			):
            return 0
      elif n == 2:
            return 1
      else:
            lowerCamelCase             =		[0, 1]
            for i in range(2 , n + 1			):
                  sequence.append(sequence[i - 1] + sequence[i - 2]			)

            return sequence[n]

def      __lowercase(						UpperCAmelCase__			):


      """simple docstring"""



      lowerCamelCase             =		0
      lowerCamelCase             =		2

      while digits < n:
            index += 1
            lowerCamelCase             =		len(str(fibonacci(UpperCAmelCase__			)			)			)

      return index

def      __lowercase(						UpperCAmelCase__ = 1000			):


      """simple docstring"""



      return fibonacci_digits_index(UpperCAmelCase__			)


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




def      __lowercase(						UpperCAmelCase__			):


      """simple docstring"""



      if n == 1 or not isinstance(UpperCAmelCase__ , UpperCAmelCase__			):
            return 0
      elif n == 2:
            return 1
      else:
            lowerCamelCase             =		[0, 1]
            for i in range(2 , n + 1			):
                  sequence.append(sequence[i - 1] + sequence[i - 2]			)

            return sequence[n]

def      __lowercase(						UpperCAmelCase__			):


      """simple docstring"""



      lowerCamelCase             =		0
      lowerCamelCase             =		2

      while digits < n:
            index += 1
            lowerCamelCase             =		len(str(fibonacci(UpperCAmelCase__			)			)			)

      return index

def      __lowercase(						UpperCAmelCase__ = 1000			):


      """simple docstring"""



      return fibonacci_digits_index(UpperCAmelCase__			)


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