Jamal wants to save $30$ files onto disks, each with $1.44~ MB$ space. $3$ of the files take up $0.8~ MB$, $12$ of the files take up $0.7 ~MB$, and the rest take up $0.4 ~MB$. It is not possible to split a file onto $2$ different disks. What is the smallest number of disks needed to store all $30$ files?

Let's think step by step and output the final answer within \boxed{}.
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