"""simple docstring"""


from __future__ import annotations






def      __UpperCAmelCase       (      lowercase ,lowercase ,lowercase ,):







  """simple docstring"""
  if (electron_conc, hole_conc, intrinsic_conc).count(0		) != 1:
    raise ValueError("""You cannot supply more or less than 2 values"""		)
  elif electron_conc < 0:
    raise ValueError("""Electron concentration cannot be negative in a semiconductor"""		)
  elif hole_conc < 0:
    raise ValueError("""Hole concentration cannot be negative in a semiconductor"""		)
  elif intrinsic_conc < 0:
    raise ValueError(
        """Intrinsic concentration cannot be negative in a semiconductor"""		)
  elif electron_conc == 0:
    return (
        "electron_conc",
        intrinsic_conc**2 / hole_conc,
    )
  elif hole_conc == 0:
    return (
        "hole_conc",
        intrinsic_conc**2 / electron_conc,
    )
  elif intrinsic_conc == 0:
    return (
        "intrinsic_conc",
        (electron_conc * hole_conc) ** 0.5,
    )
  else:
    return (-1, -1)


if __name__ == "__main__":
    import doctest

    doctest.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())))
