N, M = map(int, input().split())

MOD = 998244353

if 60 <= N or M <= (1 << (N-1)):
	a, b = 1, 1
	k = (pow(2, N, MOD) - 2) % MOD
	l = (pow(2, N-1, MOD) - 1) % MOD
	m = 1
	for i in range(1, M):
		a *= k
		a %= MOD
		k -= 1
		k %= MOD
		
		b *= l
		b %= MOD
		l -= 1
		l %= MOD
		
		m *= i
		m %= MOD
	
	a *= pow(M, -1, MOD)
	b %= MOD
	
	ans = (a - b) % MOD
	ans *= pow(2, N, MOD) - 1
	ans %= MOD
	ans *= pow(m, -1, MOD)
	ans %= MOD
	
	print(ans)
else:
	ans = 1
	a, b = pow(2, N, MOD)-1, 1
	for i in range(1, M+1):
		ans *= a
		ans %= MOD
		a -= 1
		a %= MOD
		
		b *= i
		b %= MOD
	print((ans * pow(b, -1, MOD)) % MOD)