MOD = 998244353


def comb(n, r):
    numerator, denominator = 1, 1

    for i in range(r):
        numerator = (numerator * (n - i)) % MOD
        denominator = (denominator * (i + 1)) % MOD

    return numerator * pow(denominator, MOD - 2, MOD) % MOD


N, M = [int(s) for s in input().split()]

all_cnt = comb(pow(2, N, MOD) - 1, M)

if N <= 20 and M > 2 ** (N - 1):
    print(all_cnt)
else:
    other = comb(pow(2, N - 1, MOD) - 1, M - 1) * (pow(2, N, MOD) - 1) % MOD
    print((all_cnt - other) % MOD)