[adrae5df]

So at what input value does it overflow the stack on your machine?

[cronin101]

Never on -O3 / Oz :-)

(Obviously it transforms it to a loop, so it sorta breaks the rules at compile time)

[jacquesm]

261876 here.

'0' and no number input also crash it.

[adrae5df]

Believe it or not its a weird palindrome for me: 65059

[jacquesm]

First I thought 'that's a palindrome?', then I saw what you meant. Is it repeatable?