salam
motmaennan shayad
A=1,B=2,C=1
az jomleye fard A mifahmim adadesh farde
az jomleye fard B mifahmim adadesh adadiye ke 2barabar 1adade fardnist va hamchenin agar adadesh farde tori ast ke adae A meslesh nist va 3halat barash pish miad ya 7 ya 9 ya 11
adade 11 nist zira farde B khod...