MOD = 998244353

def main():
    import sys
    N, K = map(int, sys.stdin.readline().split())
    if K > N:
        print(1 % MOD)
        return
    
    M_max = N // K
    max_n = N  # The maximum possible n for combination
    
    # Precompute factorials modulo MOD
    fact = [1] * (max_n + 1)
    for i in range(1, max_n + 1):
        fact[i] = fact[i-1] * i % MOD
    
    # Precompute inverse factorials modulo MOD
    inv_fact = [1] * (max_n + 1)
    inv_fact[max_n] = pow(fact[max_n], MOD - 2, MOD)
    for i in range(max_n - 1, -1, -1):
        inv_fact[i] = inv_fact[i + 1] * (i + 1) % MOD
    
    total = 0
    for m in range(0, M_max + 1):
        current_n = N - m * (K - 1)
        if current_n < m:
            contrib = 0
        else:
            # Compute C(current_n, m)
            contrib = fact[current_n] * inv_fact[m] % MOD
            contrib = contrib * inv_fact[current_n - m] % MOD
        total = (total + contrib) % MOD
    
    print(total)

if __name__ == "__main__":
    main()