link to question

but that isnt my doubt

so sum of all coprime numbers with n upto n = sum of all numbers part of phi(n) = phi(n)*(n/2)

i wrote the code for it.. apparently my function where i do the above computation was erroneous..

i tried stresstesting...here is my codee

its not giving correct anwer from around 1650... can someone please help? my functionname is phifunc editorial is phi

(P.S. i know that using sieve its n loglog n but both the editorial and my solution are sqrt n to it)