MOD=998244353
N,K=map(int,input().split())
if N<K:
	print(1)
else:
	dp=[0 if i else 1 for i in range(K)]
	S=[1 for i in range(K)]
	while len(S)<=N:
	    dp.append(S[len(dp)-K])
	    S.append((S[-1]+dp[-1])%MOD)
	print(S[-1])