Added the char "i" and "d" as reserved characters, which will not be converted to calculated values.
Added the char "i" and "d" as reserved characters, which will not be converted to calculated values.

w0pke/oppgavegenerator,MathGen/oppgavegenerator,w0pke/oppgavegenerator,MathGen/oppgavegenerator,w0pke/oppgavegenerator,MathGen/oppgavegenerator