def modinv(x: int, mod: int) -> int:
    """
    Z/(mod Z)上でのxの逆元

    :param x: 整数
    :param mod: 整数
    :return: x * y % mod = 1を満たすy
    """
    s, ps, r, pr = 0, 1, mod, x
    while r != 0:
        pr, (q, r) = r, divmod(pr, r)
        ps, s = s, ps - q * s
    if pr == 1:
        return ps if ps >= 0 else ps + mod
    raise ValueError("base is not invertible for the given modulus")


def factorials_with_inv(k, mod):
    """
    0! ... k! とそれらのmod逆元を求めて返す
    """
    fac = [1] * (k + 1)
    inv = [1] * (k + 1)
    t = 1
    for i in range(1, k + 1):
        t = (t * i) % mod
        fac[i] = t
    t = modinv(t, mod)
    for i in reversed(range(1, k + 1)):
        inv[i] = t
        t = (t * i) % mod
    return fac, inv


mod = 998244353

a, b = map(int, input().split())
a -= 1
b -= 1
fac, inv = factorials_with_inv(a+b, mod)

print(fac[a+b]*inv[b]%mod*inv[a]%mod)