#arc118f. [arc118_f]Growth Rate

[arc118_f]Growth Rate

Problem Statement

Given is a positive integer MM and a sequence of NN integers: A=(A1,A2,ldots,AN)A = (A_1,A_2,\\ldots,A_N). Find the number, modulo 998244353998244353, of sequences of N+1N+1 integers, X=(X1,X2,ldots,XN+1)X = (X_1,X_2, \\ldots, X_{N+1}), satisfying all of the following conditions:

  • 1leqXileqM1\\leq X_i\\leq M (1leqileqN+11\\leq i\\leq N+1)
  • AiXileqXi+1A_iX_i\\leq X_{i+1} (1leqileqN1\\leq i\\leq N)

Constraints

  • 1leqNleq10001\\leq N\\leq 1000
  • 1leqMleq10181\\leq M\\leq 10^{18}
  • 1leqAileq1091\\leq A_i\\leq 10^9
  • prodi=1NAileqM\\prod_{i=1}^N A_i \\leq M

Input

Input is given from Standard Input in the following format:

NN MM A1A_1 A2A_2 ldots\\ldots ANA_N

Output

Print the number of integer sequences satisfying the conditions, modulo 998244353998244353.


Sample Input 1

2 10
2 3

Sample Output 1

7

Seven sequences below satisfy the conditions.

  • (1,2,6)(1, 2, 6), (1,2,7)(1,2,7), (1,2,8)(1,2,8), (1,2,9)(1,2,9), (1,2,10)(1,2,10), (1,3,9)(1,3,9), (1,3,10)(1,3,10)

Sample Input 2

2 10
3 2

Sample Output 2

9

Nine sequences below satisfy the conditions.

  • (1,3,6)(1, 3, 6), (1,3,7)(1, 3, 7), (1,3,8)(1, 3, 8), (1,3,9)(1, 3, 9), (1,3,10)(1, 3, 10), (1,4,8)(1, 4, 8), (1,4,9)(1, 4, 9), (1,4,10)(1, 4, 10), (1,5,10)(1, 5, 10)

Sample Input 3

7 1000
1 2 3 4 3 2 1

Sample Output 3

225650129

Sample Input 4

5 1000000000000000000
1 1 1 1 1

Sample Output 4

307835847