# Sum Cool Squares.

**Number Theory**Level 4

There exists two 4-digit numbers \(\overline{abcd}\) such that \[\overline{ab} ^{2} + \overline{cd} ^{2} = \overline{abcd}.\] What is the sum of those two numbers?

Note:

\({a,b,c,d}\) are digits, not factors of a product.

\( a \neq 0 \).

Also, this problem is not original.