Thanks!

I really don't see the difference between "every sequence" and "all sequences", but I'm not an english native speaker.

Then your code returned 0 instead of 1, the format is:

expected +0 to equal 1 < This is the expected answer
          ^          
   This is your answer     

Yes. But when I clicked "Attempt", I've got this result - for array : [3,0,0,0,0,6,9] : expected +0 to equal 1

That test expects 1 as result.

Why, for this example, equal 0?
[3,0,0,0,0,6,9]