After visiting the ancient mosaics in Paphos, an artist decides to create several black-and-white patterns. Each pattern should be a rectangular grid of $$$n$$$ rows and $$$m$$$ columns, satisfying the following properties.
The top and bottom boundaries of the grid are connected to each other, just as the left and right boundaries are, making a torus shape. Formally, let us index rows from $$$0$$$ to $$$n-1$$$ top to bottom, and columns from $$$0$$$ to $$$m-1$$$ left to right. A cell $$$(x, y)$$$ is at the intersection of row $$$x$$$ and column $$$y$$$. Then:
Each cell is painted either black or white. A painting is valid if all of the following conditions hold:
Count the number of different valid paintings modulo $$$998\,244\,353$$$. Two paintings are different if the colors of at least one cell differ.
The only line contains two integers $$$n$$$ and $$$m$$$ ($$$3 \le n,m \le 10^6$$$), the number of rows and columns, respectively.
Print the number of valid paintings modulo $$$998\,244\,353$$$.
3 3
6
3 4
18
6 6
0
In the second example, there are $$$18$$$ valid paintings. One of them is shown below.
| Name |
|---|


