The run-length coding of a list $l$ is a list of pairs
$$
r=\left\{\left\{e_1, k_1\right\},\left\{e_2, k_2\right\}, .\left\{e_m, k_m\right\}\right\} .
$$
The $e_{\imath}$ are any expressions, the $k_{\imath}$ are integers $\geq 1$, and $m \geq 0$. The list $r$ describes (encodes) the list
$$
l=\{\underbrace{e_1, e_1, \ldots, e_1}_{k_1}, \underbrace{e_2, e_2, \ldots, e_2}_{k_2}, \ldots, \underbrace{e_m, e_m, \ldots e_m}_{k_m}\} .
$$
where each element $e_{\imath}$ occurs exactly $k_{\imath}$ times in sequence. If the list $l$ contains many repetitions of elements, the run-length coding is a short description of $l$.
Write a function RunLength $[l]$ that finds the run-length coding of $l$.
(Table Cant Copy)