n, k = map(int, input().split())
mod = 998244353
N = 10 ** 7 + 2
F = [1] * N
E = [1] * N
for i in range(2, N):
    F[i] = F[i-1]*i%mod
E[-1] = pow(F[-1], -1, mod)
for i in range(N-1, 0, -1):
    E[i-1] = E[i]*i%mod

def comb(a, b): #組合せ
    if b < 0:
        return 0
    if a < b:
        return 0
    return F[a] * E[b] * E[a-b] % mod

def perm(a, b): #順列組み合わせ
    if a < b:
        return 0
    return F[a] * E[a-b] % mod

def main(n, l, k):
    p = 2 * n - l - k + 2
    rep = 0
    tmp = n % p
    N = 2 * n
    while tmp <= N:
        rep += comb(N, tmp); rep %= mod
        tmp += p
    tmp = (l-1) % p
    while tmp <= N:
        rep -= comb(N, tmp); rep %= mod
        tmp += p
    return rep

ans = main(n, n, n-k) - main(n, n, n-k+1)
ans %= mod
print(ans)