def hanoi(x):
    if x == 1:
        return 1
    if x not in li:
        li[x] = (hanoi(x-1)*2+1) % 998244353
        return li[x]
    else:
        return li[x]

li = {}
n, l = map(int, input().split())
m = n//l if n%l == 0 else n//l+1
print(hanoi(m))