ACPC10A

ACPC10A

#include<iostream>
using namespace std;
int main()
{
long int a,b,c;
while(1)
{
cin>>a>>b>>c;
if(a==0&&b==0&&c==0)
{break;}
else if(b-a==c-b)
{
cout<<"AP"<<" "<<(b-a)+c<<endl;
}
else if(b/a==c/b)
{
cout<<"GP"<<" "<<(b/a)*c<<endl;
}
}
return 0;
}