n,k=map(int,input().split())
M=998244353
fa=[1,1]
fb=[1,1]
for i in range(2,n+1):
  fa+=[fa[-1]*i%M]
  fb+=[fb[-1]*(M//i)*fb[M%i]*fa[M%i-1]*(-1)%M]
g=1
for i in range(1,n+1):
  if n-i*k>=0:
    g+=fa[n-i*k+i]*fb[n-i*k]*fb[i]
    g%=M
print(g)