import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 998244353; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, L = getlist()
	ans = pow(2, int((N - 1) // L + 1), con) - 1
	print(ans)




if __name__ == '__main__':
	main()