Is there any way in maple to solve this to give answer back to plaintext from cipher-text.

toletter := proc (num) local cs, cn, sl, ltable, ans, ii; ltable := table([0 = "A", 1 = "B", 2 = "C", 3 = "D", 4 = "E", 5 = "F", 6 = "G", 7 = "H", 8 = "I", 9 = "J", 10 = "K", 11 = "L", 12 = "M", 13 = "N", 14 = "O", 15 = "P", 16 = "Q", 17 = "R", 18 = "S", 19 = "T", 20 = "U", 21 = "V", 22 = "W", 23 = "X", 24 = "Y", 25 = "Z"]); cn := num; sl := floor((1/2)*trunc(evalf(log10(cn))))+1; ans := " "; for ii to sl do cn := (1/100)*cn; cs := ltatble[100*frac(cn)]; ans := cat(cs, ans); cn := trunc(cn) end do; RETURN(ans) end proc

This is because of the answer that I get is not in letter form:

toletter(plaintext);
(ltatble[17]) || (ltatble[4]) || (ltatble[19]) || (ltatble[20]) || 

  (ltatble[17]) || (ltatble[13]) || (ltatble[19]) || (ltatble[14]

  ) || (ltatble[12]) || (ltatble[0]) || (ltatble[8]) || (ltatble[

  13]) || (ltatble[3]) || (ltatble[4]) || (ltatble[2]) || (

  ltatble[10]) || " "