MOD = 998244353

def count_set_bits(x):
    return bin(x).count('1')

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

M = count_set_bits(N)
L = count_set_bits(K)

a = pow(3, M, MOD)
b = pow(2, L, MOD)

result = (a + b - 1) % MOD

print(result)