Hello,
I am not that strong in DP but I have been trying hard to understand the problem. I tried coming up with a solution however got WA. I cannot completely understand the hints given before, PLEASE HELP !!!

There are two dp-approaches already described on the webboard

So I have accepted with dp
I have two dp
Stirling numbers of the second kind and factorial
Then precalculate answer array

I have seen the 2 DP solutions however I still don't understand how do they arrive at the relation?
Can you describe in detail if possible, Please !

There are X groups consisting of equal numbers.
X=1,2,..n.

What does it mean, to put some '<' and '>' signs between them?
It is just to define some order relation.
Just assign one group as the greatest, another group as the second greatest etc.

So we find number of ways to make groups and multiply it by number of ways to make ordering

https://ideone.com/00UUdf