Is using goto a legitimate way to break out of two loops?

Question

I am solving problem 9 on the Project Euler. In my solution I use a "goto" statement to break out of two for loops. The Problem is the following:

Answer 1

I can't think of a better alternative. But one alternative not using goto would be modifying the first for-loop:

for (a = 1; a

Then break out of the second for-loop. That will work assuming the result will never be -1 after the second for-loop has been broken by break.