sumUntil :: (Num a) => (a -> Bool) -> [a] -> a
sumUntil f (x:y:xs) = if f x
                      then x
                      else sumUntil f ((x + y):xs)
sumUntil :: (Num a) => (a -> Bool) -> [a] -> a
sumUntil f (x:y:xs) = if f x
                      then x
                      else sumUntil f ((x + y):xs)
sumUntil f (x:y:xs) = if f x
                      then x
                      else sumUntil f ((x + y):xs)