\(\overline{AB}\) is the hypotenuse of a right triangle \(ABC\). Median \(\overline{AD}\) has length \(7\) and median \(\overline{BE}\) has length \(4\). The length of \(\overline{AB}\) is in the form of a\sqrt{b}. Please give the value of a + b.

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