MOD = 998244353

N, K = map(int, input().split())

max_m = N // K

max_fact = N  # Maximum possible n is N when m=0, K-1=0 (if K=1)

# Precompute factorial and inverse factorial modulo MOD
fact = [1] * (max_fact + 1)
for i in range(1, max_fact + 1):
    fact[i] = fact[i-1] * i % MOD

inv_fact = [1] * (max_fact + 1)
inv_fact[max_fact] = pow(fact[max_fact], MOD-2, MOD)
for i in range(max_fact - 1, -1, -1):
    inv_fact[i] = inv_fact[i+1] * (i+1) % MOD

ans = 0
for m in range(0, max_m + 1):
    n = N - m * (K - 1)
    if n < m or n < 0:
        continue
    # Calculate combination(n, m)
    numerator = fact[n]
    denominator = (inv_fact[m] * inv_fact[n - m]) % MOD
    comb = (numerator * denominator) % MOD
    ans = (ans + comb) % MOD

print(ans)