Question about find(1): How to invoke multiple commands in exec?

[Andreas R.]

If for example I want to count all the files in a subdirectories of the 
current directory, I thoght I would need something like that:

find . -type d -exec find "{}" -print | wc -l \;
find: missing argument to `-exec'
wc: ;: No such file or directory

Parenthesing doesn't help:
find . -type d -exec (find "{}" -print | wc -l) \;
bash: syntax error near unexpected token `('

Escaping the parentheses doesn't help either:
find . -type d -exec \( find "{}" -print | wc -l \) \;
find: missing argument to `-exec'
wc: ): No such file or directory
wc: ;: No such file or directory
      0 total

Does anyone has an idea how to do it the right way?