let rec fact n =
  if n = 0 then 1 else n * fact (n - 1)
;;
let bi_c  n k =
  fact n / ((fact k) * (fact (n - k)))
;;

let rec rgb a b n k x sum  =
  if x <= 0 then sum
  else
    let y = (k - a * x) / b in
    if a * x + b * y = k && 0 <= y && y <= n then
      rgb a b n k (x - 1) (sum +  (bi_c n x) * (bi_c n y))
    else
      rgb a b n k (x - 1) (sum)
  
let () =
  let n, a, b, k = Scanf.scanf "%d %d %d %d"
                     (fun n a b k -> n, a, b, k) in
  (rgb a b n k n 0) mod 998244353 
|> print_int 
