Triangle Count (Easy)

**This is the easy version of the problem. It is worth the usual $100$ points in all divisions. Here, you need to solve the problem only for the entire array.** For an array $B$ containing $M$ **distinct** integers, say $[B_1, B_2, \ldots, B_M]$, we define $f(B)$ to be the number of distinct integers $X$ that satisfy the following conditions: - $X \ge 1$; and - There exists $1 \le i < j \le M$ su