mod = 998244353

N, M = map(int, input().split())
if N % 2 == 1:
	print(((pow(M, N, mod) + 1) * pow(M + 1, -1, mod) - 1) % mod)
else:
	print((pow(M, N, mod) - 1) * pow(M + 1, -1, mod) % mod)