Description:
None
Input Format:
The first line contains one integer $$$n$$$ ($$$1 \leq n \leq 10^5$$$) — the length of the array $$$a$$$.
The second line contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$0 \leq a_i \leq 2$$$) — the array $$$a$$$.
Output Format:
Output a single integer — the number of solutions, modulo $$$20240401$$$.
Note:
In the first sample, the array looks like this:
$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{darkgreen}{2} $$$$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{darkgreen}{2} $$$$$$ \color{gray}{0} $$$
Obviously, the answer here is $$$1 \pmod{20240401}$$$.
In the second sample, the array looks like this:
$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{darkgreen}{2} $$$$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{gray}{0} $$$
I do not know why the answer here is $$$2 \pmod{20240401}$$$, I had to take a guess.
In the third sample, the array looks like this:
$$$ \color{gray}{0} $$$$$$ \color{blue}{1} $$$$$$ \color{darkgreen}{2} $$$$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{blue}{1} $$$$$$ \color{gray}{0} $$$
If the answer here is not $$$0 \pmod{20240401}$$$, I am literally going to explode.