input: Text: DUST UNTO DUST By LYMAN D. HINCKLEY It was alien but was it dead, this towering, sinister city of metal that glittered malignantly before the cautious advance of three awed space-scouters. Martin set the lifeboat down carefully, with all the attention one usually exercises in a situation where the totally unexpected has occurred, and he and his two companions sat and stared in awed silence at the city a quarter-mile away. He saw the dull, black walls of buildings shouldering grimly into the twilight sky, saw the sheared edge where the metal city ended and the barren earth began... and he remembered observing, even before they landed, the too-strict geometry imposed on the entire construction. He frowned. The first impression was... malignant. Wass, blond and slight, with enough nose for three or four men, unbuckled his safety belt and stood up. "Shall we, gentlemen?" and with a graceful movement of hand and arm he indicated the waiting city. Martin led Wass, and the gangling, scarecrow-like Rodney, through the stillness overlaying the barren ground. There was only the twilight sky, and harsh and black against it, the convoluted earth. And the city. Malignant. He wondered, again, what beings would choose to build a city—even a city like this one—in such surroundings. The men from the ship knew only the surface facts about this waiting geometric discovery. Theirs was the eleventh inter-planetary flight, and the previous ten, in the time allowed them for exploration while this planet was still close enough to their own to permit a safe return in their ships, had not spotted the city. But the eleventh expedition had, an hour ago, with just thirteen hours left during which a return flight could be safely started. So far as was known, this was the only city on the planet—the planet without any life at all, save tiny mosses, for a million years or more. And no matter which direction from
  Question: How many other expeditions ventured to the planet without noticing the city?
  
   (A) 11
   (B) 10
   (C) 0
   (D) 7
  Answer:
output: 10