input.txt

/****This**********/
/**************/
/*************************
i = 333;        ******************/       */
aDs///123
iiii == 3@33;
IF is not and id
//this is a comment*/sdsfre
int g 4 cd (int u, int v)      {
if(v == >= 0) return/*a comment*/ u;
else ret_urn gcd(vxxxxxxvvvvv, u-u/v*v);
       /* u-u/v*v == u mod v*/
!
}

return void while       void main()

!=


/* skipme */
dontskipone /* skipme */ dontskiptwo
dontskipthree/*/*skipme/* @@@ /** /skipme/**/dontskipfour
dontskipfive/*skipme
skipme skipme*/dontskipsix
ifx abc_def ghi@jkl @ _//skipme
+-*/[]{}()
        ==     = > < >= <= ===
123 a456
        if while else void int return
whilex elsex voidx intx returnx ifif ifwhile

int main(void x, int y) {
    return 0;
}