flowchart LR
  Start[Start]
  Stop[Stop]
  Start --> Dollar([<tt>$</tt>])
  Dollar --> Digit([<tt>0</tt>..<tt>9</tt> / <tt>A</tt>..<tt>F</tt> / <tt>a</tt>..<tt>f</tt>])
  Digit --> Stop
  Digit --> NextDigit([<tt>0</tt>..<tt>9</tt> / <tt>A</tt>..<tt>F</tt> / <tt>a</tt>..<tt>f</tt> / <tt>_</tt>])
  NextDigit --> NextDigit
  NextDigit --> Stop