import sys # sys.setrecursionlimit(200005) int1 = lambda x: int(x)-1 p2D = lambda x: print(*x, sep="\n") def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() # dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] inf = 10**16 md = 998244353 # md = 10**9+7 def nCr(com_n, com_r): if com_r < 0: return 0 if com_n < com_r: return 0 return fac[com_n]*ifac[com_r]%md*ifac[com_n-com_r]%md # 準備 n_max = 300005 fac = [1] for i in range(1, n_max+1): fac.append(fac[-1]*i%md) ifac = [1]*(n_max+1) ifac[n_max] = pow(fac[n_max], md-2, md) for i in range(n_max-1, 1, -1): ifac[i] = ifac[i+1]*(i+1)%md n, m, a, b = LI() ans = 0 for s in range(1, m+1): d = min(b, m-s) c = d-(n-1)*a if c < 0: break ans += nCr(n-1+c, c) ans %= md ans *= fac[n] print(ans%md)