import Control.Monad (replicateM)
import Data.Int (Int64)
import qualified Data.Map.Strict as M

type Count = Int
type Counter a = M.Map a Count

addElement :: Ord a => a -> Counter a -> Counter a
addElement x = M.insertWith (+) x 1

buildCounter :: Ord a => [a] -> Counter a
buildCounter = foldr addElement M.empty

computeTotalCost :: Integral a => a -> a -> [a] -> a
computeTotalCost p1 p2 rs = sum $ calcCost <$> M.elems ctr
    where
        ctr = buildCounter rs
        calcCost v = if v > 1 then fromIntegral (v - 1) * (p1 + p2) else 0

main :: IO ()
main = do
    p1 <- readLn :: IO Int64
    p2 <- readLn :: IO Int64
    n <- readLn :: IO Int
    rs <- replicateM n readLn :: IO [Int64]
    print $ computeTotalCost p1 p2 rs