Problem Statement
You are given a permutation $P = (P_1, P_2, \ldots, P_N)$ of $(1, 2, \ldots, N)$.
Print the number of integer sequences $A = (A_1, A_2, \ldots, A_N)$ of length $N$ that satisfy both of the conditions below, modulo $998244353$.
$1 \leq A_i \leq M$for every$i = 1, 2, \ldots, N$.- The integer sequence
$A$is lexicographically smaller than the integer sequence$(A_{P_1}, A_{P_2}, \ldots, A_{P_N})$.
What is lexicographical order? An integer sequence $X = (X_1,X_2,\ldots,X_N)$ is ** lexicographically smaller** than an integer sequence $Y = (Y_1,Y_2,\ldots,Y_N)$ when there is an integer $1 \leq i \leq N$ that satisfies both of the conditions below. For all integers $j$ ($1 \leq j \leq i-1$), $X_j=Y_j$. $X_i < Y_i$
Constraints
$1 \leq N \leq 2 \times 10^5$$1 \leq M \leq 10^9$$1 \leq P_i \leq N$$i \neq j \implies P_i \neq P_j$- All values in the input are integers.
Input
The input is given from Standard Input in the following format:
N M
P_1 P_2 \ldots P_N
Output
Print the number of integer sequences $A$ of length $N$ that satisfy both of the conditions in the Problem Statement, modulo $998244353$.
样例
4 2
4 1 3 2
6
1 1
1
0
20 100000
11 15 3 20 17 6 1 9 5 19 10 16 7 8 12 2 18 14 4 13
55365742
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