Store the unique characters corresponding to word and number
char [ ] k = { ' z ' , ' w ' , ' u ' , ' x ' , ' g ' , ' h ' , ' o ' , ' f ' , ' v ' , ' i ' } ; string [ ] l = { " zero " , " two " , " four " , " six " , " eight " , " three " , " one " , " five " , " seven " , " nine " } ; int [ ] c = { 0 , 2 , 4 , 6 , 8 , 3 , 1 , 5 , 7 , 9 } ;