how to make the function "length" from "map" and "sum"

Hello, I am working my way through Simon Thompson's Haskell book, and one exercise has me baffled. That is "how would you define the "length" function using "map" and "sum" "? Any help on this would be appreciated. John Mann ===== "I'd rather be debugging...." - Anon __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com