Equalize the Array

You are given an array $A_1,A_2,…,A_N$, consisting of $N$ integers. Let's define a function $F(M)$, where $M \leq N$, as an integer denoting the minimum number of the following operations required to make all the values $A_1,A_2,…,A_M$, equal: Choose a non-empty sequence $S = i_1, i_2, …, i_{2k + 1}$ such that $i_1 < i_2 < i_3 < .... < i_{2k + 1}$, and then do **any one** of the following : 1)