Confusion
For this example, why is the answer 3?\n\n4\n[[1],[2],[3],[4]]\n[[1,2],[3,4]]\n\nwe can simply teach 1 language 2 and teach 3 language 4, which leads to answer 
For this example, why is the answer 3?\n\n4\n[[1],[2],[3],[4]]\n[[1,2],[3,4]]\n\nwe can simply teach 1 language 2 and teach 3 language 4, which leads to answer 2.
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