SOLVE
LATER
Let's define $$2$$ functions a function $$F(i)$$ and $$Val(i,j)$$ for an Array $$A$$ of size $$N$$ as follows:
$$F(i) =$$ $$ \sum_{j=i+1}^{N} Val(i,j) $$
$$ Val(i,j) =$$ $$1$$ ,if $$A[i] < A[j]$$, else, $$Val(i,j) =$$ $$0$$.
Now, Vanya has been given one such array $$A$$ of size $$N$$ and an integer $$K$$. She needs to find the number of Distinct Unordered Pairs of elements $$(a,b)$$ in array $$A$$ such that $$F(a) +F(b) \ge K$$.
Input Format:
The first line contains $$2$$ space separated integers $$N$$ and $$K$$ denoting the size of array $$A$$ and the integer $$k$$ from the description given above. The next line contains $$N$$ space separated integers denoting the elements of array $$A$$ .
Output Format:
You need to print the required answer on a single line.
Constraints:
Subtask 1: (Worth 40% of the total points):
$$ 1 \le N \le 5000 $$
$$ 1 \le A[i] \le 10^5 $$
$$ 0 \le K \le 10^4 $$
Subtask 2: (Worth 60% of the total points) :
$$ 1 \le N \le 10^6 $$
$$ 1 \le A[i] \le 10^9 $$
$$ 0 \le K \le 10^9 $$
Here the values of Function $$F(x)$$ for all the elements of Array $$A$$ from $$1$$ to $$N$$ are:
$$ [7,5,5,4,3,2,0,0]$$
So, the following 5 unordered pairs are considered:
$$ (1,2) $$
$$ (1,3) $$
$$ (1,4) $$
$$ (1, 5) $$
$$ (2,3) $$