This task involves creating questions from a given passage that involve some kind of complex reasoning (including numerical reasoning).
The generated questions must require looking at more than one part of the passage to answer. Try to use a variety of reasoning types in your questions (some of the sample reasoning types are illustrated in the 'positive examples' field) and also have a variety of answer types (spans, numbers, dates). A span is a continuous phrase taken directly from the passage or question. In such questions, the answer spans are recommended to be five words. Questions with answer type "number", are expected to start with "How many". For instance, "How long did an event last?" can be phrased as "How many years did an event last?". To increase diversity, try to create more questions for which the answer will be multiple spans. Please create questions that require AT LEAST 2 arithmetic operations as illustrated in the 'positive examples' field. You are encouraged to try DIFFERENT COMBINATIONS of operations and not just limit to the combinations shown in those examples. The more challenging questions you create, the better it is.
Q: Passage: From 1231, Goryeo was intermittently invaded by the Mongol Empire. During this time, Goryeo was controlled by a military regime led by the Choe family. In 1232 the government under the nominal king fled to Ganghwa Island, which Mongol horse riders were unable to land on, and resisted the Mongol invasion. Unfortunately because of its fragile foundation, Goryeo faced frequent rebellions. The 1258 rebellion resulted in the establishment of Ssangseong and Dongnyeong Prefectures by the Mongols. Unlike these rebels, the Sambyeolcho were an organ of the military government. They were organized by the Choe family to maintain security. However, unlike the Choe private guards unit , the Sambyeolcho assumed public functions performed by police and combat forces, effectively replacing the Six Divisions of the military. In 1258, Choe Ui, the fourth of the Choe family, was overthrown by Kim Jun using the Sambyeolcho. Kim Jun took a pro-Mongol policy and sent Crown Prince Wang Jeon to the Mongol Empire. At the same time, King Gojong and the crown prince approached the Mongols to restore power from Kim Jun. In 1268, however, Kim Jun was annihilated by the Sambyeolcho under the order of Im Yeon. The next year, Im Yeon's attempt to replace King Wonjong was reversed by the crown prince with the help from the Mongol force. In 1270, Im Yeon's successor Im Yumu was killed by the pro-Mongol faction using the Sambyeolcho. It marked the end of the military regime.
A:
How many Mongol prefectures were established due to the rebellion in 1258?