Problem10368--ABC327 —— G - Many Good Tuple Problems

10368: ABC327 —— G - Many Good Tuple Problems

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Time Limit : 1.000 sec  Memory Limit : 512 MiB

Description

> The definition of a good pair of sequences in this problem is the same as in Problem D.

A pair of sequences of length $M$ consisting of positive integers at most $N$, $(S, T) = ((S_1, S_2, \dots, S_M), (T_1, T_2, \dots, T_M))$, is said to be a good pair of sequences when $(S, T)$ satisfies the following condition.

-   There exists a sequence $X = (X_1, X_2, \dots, X_N)$ of length $N$ consisting of $0$ and $1$ that satisfies the following condition:
    -   $X_{S_i} \neq X_{T_i}$ for each $i=1, 2, \dots, M$.

Among the $N^{2M}$ possible pairs of sequences of length $M$ consisting of positive integers at most $N$, $(A, B) = ((A_1, A_2, \dots, A_M), (B_1, B_2, \dots, B_M))$, find the number, modulo $998244353$, of those that are good pairs of sequences.

Input

The input is given from Standard Input in the following format:

```
$N$ $M$
```

Output

Print the number, modulo $998244353$, of pairs of sequences of length $M$ consisting of positive integers at most $N$ that are good pairs of sequences.

Constraints

-   $1 \leq N \leq 30$
-   $1 \leq M \leq 10^9$
-   $N$ and $M$ are integers.

Sample 1 Input

3 2

Sample 1 Output

36
For example, if A=(1,2),B=(2,3), then (A,B) is a good pair of sequences. Indeed, if we set X=(0,1,0), then X is a sequence of length N consisting of 0 and 1 that satisfies $X_{A_1}≠X_{B_1}$ and $X_{A_2}≠X_{B_2}$. Thus, (A,B) satisfies the condition of being a good pair of sequences.
There are a total of 36 good pairs of sequences, so print this number.

Sample 2 Input

3 3

Sample 2 Output

168

Sample 3 Input

12 34

Sample 3 Output

539029838

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