LaTeX: left arrow to sample an element uniformly at random

Here is a command to draw a left arrow with a dollar sign. It is commonly used to denote a variable assignment uniformly at random from a given set.

    $\alpha \overset{{\scriptscriptstyle\$}}{\leftarrow} \mathbb{G}$

Some people use the letter R instead of the dollar sign $. Here are a few variants:

    $\alpha \overset{\$}{\leftarrow}  \mathbb{G}$

    $\alpha \overset{{\scriptscriptstyle \operatorname{R}}}{\leftarrow}  \mathbb{G}$

For some reason, I didn’t manage to find how to draw this arrow elsewhere on the Internet. Let me know if there is a better way.