Added

zruF I thought you got it. Read what myjinxin2015 wrote. x is always the first element (except when x is 1 ofc).

Yes, I used some algorithm and because of the chosen methods it was timing out, changed the methods and it worked.

You need a better approach.

I use a seive method and end correctly the test in 443ms but the submit exceed the time limit.
it's possible ?

Must add the support for Python 3

Cavolo almeno la somma ci potevo arrivare... bello l'alfabeto scritto a mano XD

This is not an issue, it's a question ;-)

Did you see the comment right next to the function in the initial code? Or did you looked at the sample tests? ;-)