integer::N,i,sum=0
integer,allocatable,dimension(:)::C

read *,N
allocate(C(N))

read *,C(:)

do i=1,N
 sum=sum+C(i)
end do

if(maxval(C(:))>=3 .or. mod(sum,2)==2) then
 print *,'B'
else
 print *,'A'
end if

end