I am trying to parse an input stream where the first line tells me how many lines of data there are. I'm ending up with the following code, and it works, but I think there is a better way. Is there?

main = do
    numCases <- getLine
    proc $ read numCases

proc :: Integer -> IO ()
proc numCases
     | numCases == 0 = return ()
     | otherwise = do
         str <- getLine
         putStrLn $ findNextPalin str
         proc (numCases - 1)

Note: The code solves the Sphere problem https://www.spoj.pl/problems/PALIN/ but I didn't think posting the rest of the code would impact the discussion of what to do here.