MOD = 998244353

def main():
    import sys
    N, K = map(int, sys.stdin.readline().split())
    
    # Calculate d = popcount(N & ~K)
    d_bits = N & (~K)
    d = bin(d_bits).count('1')
    
    # Calculate m = popcount(N & K)
    m_bits = N & K
    m = bin(m_bits).count('1')
    
    # Compute 3^d mod MOD
    pow3 = pow(3, d, MOD)
    
    # Compute 4^m mod MOD
    pow4 = pow(4, m, MOD)
    
    # Result is (pow3 * pow4) % MOD
    result = (pow3 * pow4) % MOD
    print(result)

if __name__ == '__main__':
    main()