We need to convert the symbols and numerals into their corresponding English letters:
rsFrs is a letter, so it stays as an English letter.
rs6rs is a numeral, and 6 is converted into "six."
rsGrs is a letter.
rs@rs is a symbol, which is converted into numeral 0, and 0 is converted into "zero."
rs7rs is a numeral, which is converted into "seven."
rsNrs is a letter.
rsSrs is a letter.
rs2rs is a numeral, which is converted into "two."
rsTrs is a letter.
rsYrs is a letter.
rs5rs is a numeral, which is converted into "five."
rsOrs is a letter.
rsGrs is a letter.
rs#rs is a symbol, which is converted into numeral 0, and 0 is converted into "zero."
rsQrs is a letter.
rs8rs is a numeral, which is converted into "eight."
rsMrs is a letter.
rs\rs* is a symbol, which is converted into numeral 1, and 1 is converted into "one."
rs9rs is a numeral, which is converted into "nine."
rsZrs is a letter.
rs%rs is a symbol, which is converted into numeral 1, and 1 is converted into "one."
rsBrs is a letter.
rsArs is a letter.
rs4rs is a numeral, which is converted into "four."
Now, let's count the English letters:
The English letters are: rsF, G, N, S, T, Y, O, G, Q, M, Z, B, Ars.
There are 13 English letters.
Thus, the number of converted English letters is rs13rs.