I am getting WA in Spoj problem http://www.spoj.com/problems/ACPC10A/
int main()
{
int a,b,c;
cin>>a>>b>>c;
while(a!=0&&b!=0&&c!=0)
{
if((2*b)==(a+c))
cout<<"AP "<<c+(c-b)<<"\n";
else if((b*b)==(a*c))
cout<<"GP "<<c*(c/b)<<"\n";
cin>>a>>b>>c;
}
return 0;
}