main :: IO ()
main = interact $ show . solve . map read . words

solve :: [Int] -> Int
solve [vegi, meet, n, total] 
    | n > meet  = 0
    | otherwise = if i * n > meet 
                        then meet `div` n
                        else i
    where
        i = length $ filter (<= total) $ map (* (n + 1)) [1..vegi]