Instructions: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Input: Passage: Bartlett's decision to deposit stores on the ice ensured that an ice camp, known as "Shipwreck Camp", was more or less established by the time Karluk sank. Two shelters had been built, one a snow igloo with a canvas roof, the other constructed from packing cases. To the latter was added a kitchen with a large stove rescued from Karluk's engine room. A small, separate shelter was built for the five Inuit, and a rough perimeter created from coal bags and assorted containers. In McKinlay's words, the camp provided "substantial and comfortable houses on which we could rely for shelter for a long time." Stores were plentiful, and the party was able to eat well. Much of the time in the first days of the camp was spent preparing and adjusting clothing and sleeping gear, in readiness for the forthcoming march to Wrangel Island. The ice drift was slowly moving the camp in the direction of the island, but as yet there was insufficient daylight to attempt the march.Amid this activity Mackay and Murray, now joined by the anthropologist Henri Beuchat, played little part in the general life of the camp and expressed their determination to leave it, independently, as soon as possible. Bartlett wanted to wait for the longer daylight hours of February before attempting the march, but was persuaded by McKinlay and Mamen to send a trailbreaking group to set up an advance camp on Wrangel Island. A party of four, led by Karluk's first officer Alexander Anderson and including crew members Charles Barker, John Brady and Edmund Golightly, left Shipwreck Camp on 21 January with instructions from Bartlett to establish their camp at or near Berry Point on the north shore of Wrangel Island. On 4 February Bjarne Mamen, who accompanied the party as a scout, returned to Shipwreck Camp and reported that he had left the group a few miles short of land that was evidently not Wrangel Island, and was probably Herald Island, 38 miles (61 km) from their intended destination. This was the last sighting of Anderson's party; their ultimate fate was not established until ten years later, when their remains were found on Herald Island.
Output:
What were the two shelters built from?