-- yukicoder My Practice
-- author: Leonardone @ NEETSDKASU

import Data.List
import qualified Data.Map as Map

main = do
    w <- readLn
    h <- readLn
    n <- getLine
    sk <- getContents
    putStrLn $ solve w h n sk

solve w h n sk = show ans where
    (sm, km) = foldl fn (Map.empty, Map.empty) $ map words $ lines sk where
        fn (sm, km) (s:k:_) = (fx s sm, fx k km) where
            fx t tm = Map.insert t (case Map.lookup t tm of { Just x -> x + 1; _ -> 1 }) tm
    c1 = Map.fold (\a b -> b + (h - a)) 0 sm
    c2 = (w - (Map.size sm)) * (Map.size km)
    ans = c1 + c2