408685: GYM103261 L Not Our Problem
Description
Someone (not me!) calls an array of length $$$n$$$ consisting of non-negative integers good if and only if $$$a_{i} \cdot a_{i + 1} \cdot \min (a_{i}, a_{i + 1}) \le C$$$ holds for all $$$1 \le i < n$$$.
Someone else (we have nothing to do with them!) gives you an array of length $$$n$$$ with some blank positions. Calculate the number of ways to fill in the blank positions so that the array is good, or determine that there are infinitely many ways. If the answer is finite, print it modulo $$$998\,244\,353$$$.
InputThe first line contains two integers $$$n$$$ and $$$C$$$ ($$$1 \le n \le 10^{6}$$$, $$$0 \le C \le 10^{18}$$$) — the length of the array and the constraint on the product.
The second line contains the array $$$a$$$. Each element is either -1, which means that it needs to be filled, or between $$$0$$$ and $$$10^{18}$$$, inclusive.
OutputIf the number of ways is infinite, print $$$-1$$$, otherwise print the number of ways modulo $$$998\,244\,353$$$.
ExamplesInput4 100 -1 7 2 -1Output
104Input
4 100 10 -1 -1 1Output
240Input
1 0 -1Output
-1Input
2 10 10 10Output
0