$=======$ Estimated time $3$mins$======$

Fill in the correct answer: $//$ Don't add anything extra! No spoces.

typedef struct st $\{$ int Id; st$*$ next; $\}$ NODE;

void fun$1($NODE$*$ head$)$

$\{$

if $($head $==$ NULL $||$ head $$ next $==$ NULL$)$

return;

fund $($head $$ next$)$;

cout &s hesd$->$Id;

fun$1($nead $$ next$)$;

$\}|$

Consider that head points to linked$-$list with entries$($Id$)$: $123$

The output of statement: fun$1($head$)$; is