You will be given a definition of a task first, then some input of the task.
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.

Passage: In the mean time, Maha Nawrahta opened the southern front on 23 October 1765 in three directions. He had 20,000 to 30,000 under his command. A small army invaded by the Three Pagodas Pass towards Suphanburi. Another small army invaded down the Tenasserim coast towards Mergui and Tenasserim town. However, the main thrust of his attack was at Kanchanaburi. His 20,000-strong main southern army invaded via the Myitta Pass. Kanchanaburi fell with little resistance. The main reason for the quick fall of Kanchanaburi could be that the Burmese were more battle-hardened. But it could also be that the Siamese command miscalculated where the Burmese main attack would come from, and had not sufficiently reinforced the fort to withstand a major attack. Judging by the Siamese chronicles' reporting of the main attack route, the Siamese command appeared to have believed that the main Burmese attack would come from the Gulf of Siam coastline, instead of the most obvious and shortest route via Kanchanaburi. The Siamese sources say that Maha Nawrahta's main invasion route came from southern Tenasserim, crossing the Tenasserim range at Chumphon and Phetburi. The path is totally different from the Kanchanaburi route reported by the Burmese chronicles. Historian Kyaw Thet specifically adds that the main attack route was via the Myitta Pass.
Output:
How many Maha Nawrahta opened the southern front?