from sys import stdin
input = stdin.readline

MOD = 998244353

def inverse(n, d):
    return n * pow(d, -1, MOD) % MOD

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

top = 1
s = (pow(2, N-1, MOD)-1)%MOD
bottom = 1
for i in range(1, M):
    top *= s-i+1
    top %= MOD
    bottom *= i
    bottom %= MOD

top2 = 1
s2 = (pow(2, N, MOD)-1)%MOD
bottom2 = 1
for i in range(1, M+1):
    top2 *= s2-i+1
    top2 %= MOD
    bottom2 *= i
    bottom2 %= MOD

print((inverse(top2, bottom2) - inverse(top, bottom)*(pow(2, N, MOD)-1)%MOD)%MOD)