Suppose I add a new word count function to my .emacs file to count words:

(defun word-count nil "Count words in buffer" (interactive) (shell-command-on-region (point-min) (point-max) "wc -w"))

I remember there being a way to run a function by typing the function name, but I don't remember how. What key sequence do I type before I type word-count, enter?