VERBOSE is #defined at the top of this file (with no value – just being defined at all is what #ifdef
checks for). Wrap a debug printf in #ifdef VERBOSE / #endif so it prints before the normal output, exactly
as described in the lesson’s example.
In a real project, VERBOSE (or a name like it) would typically be defined per build – present when compiling a
debug version, absent from a release build – rather than hardcoded in the source like this. Here it’s fixed so
the exercise has one deterministic, gradable behavior; the mechanism is identical either way.