Algebra Level 4

If $$1 +\sqrt{2} + \sqrt{5} + \sqrt{10}$$ = $$\sqrt{a + \sqrt{b + \sqrt{c + \sqrt{d}}}}$$ , where $$a, b, c,$$ and $$d$$ are integers, find $$a + b + c + d.$$

Inspired from Math is Radical 2.

×