Examine the following sequence closely and respond to the question that follows.
$$\text{R K }59\#\text{ B }2\%\ast \text{ E ? A }8\text{ L }\$\text{ I }4\text{ S V }7\text{ ! C }6\text{ N }\text{@}\text{ H }13\text{ D}$$

How many letters are there, each of which is immediately preceded and immediately followed by a symbol?

We need to find patterns of the type: **Symbol $\to$ Letter $\to$ Symbol**.
Let's check each letter in the sequence:

* $\text{R}$: Preceded by nothing.
* $\text{K}$: Preceded by letter $\text{R}$, followed by number $5$.
* $\text{B}$: Preceded by symbol $\#$, followed by number $2$.
* $\text{E}$: Preceded by symbol $\ast$, followed by symbol $?$. Thus, the pattern is: $\ast \text{E?}$ (Symbol-Letter-Symbol). (Count = 1)
* $\text{A}$: Preceded by symbol $?$, followed by number $8$.
* $\text{L}$: Preceded by number $8$, followed by symbol \$.\ast$ \text{I}$:Precededbysymbol$ \
$$,followedbynumber$ 4$.\ast$ \text{S}$:Precededbynumber$ 4$,followedbyletter$ \text{V}$.\ast$ \text{V}$:Precededbyletter$ \text{S}$,followedbynumber$ 7$.\ast$ \text{C}$:Precededbysymbol$!$,followedbynumber$ 6$.\ast$ \text{N}$:Precededbynumber$ 6$,followedbysymbol$ @$.\ast$ \text{H}$:Precededbysymbol$ @$,followedbynumber$ 1$.\ast$ \text{D}$:Precededbynumber$ 3$,followedbynothing.Only$ 1$letter($ \text{E}$) satisfies the condition.