






"""simple docstring"""
def 							snake_case (  A__		):
			return "".join(chr(ord(A__		) - 32		) if "a" <= char <= "z" else char for char in word		)


if __name__ == "__main__":
			from doctest import testmod

			testmod()




"""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())))
