Transformation

Let's take a positive integer $n$. We will change it as follows: if the number is even, divide it by $2$; if it is odd, add $1$ to it. After several such changes, we will always obtain $1$. For example, starting from $11$, we obtain $12$, then $6$, $3$, $4$, $2$, and finally $1$. Thus, to obtain $1$ from $11$, we need to make $6$ changes.

Given a positive integer, determine the number of changes required to obtain $1$.