/TT - TIENTE

              Uses Crt;
        Var     n,i,count:longint;
                sa,s:int64;
                a,x:array[1..1000] of longint;
                ketqua:array[1..1000000] of ansistring;
        Procedure Ktra;
        var i:longint;
        begin
            if sa=(s-sa) then
            begin
                inc(count);
                ketqua[count]:='';
                for i:=1 to n do if x[i]=0 then ketqua[count]:=ketqua[count]+'A '
                        else ketqua[count]:=ketqua[count]+'B ';
            end;
        end;
        Procedure TienTe(i:longint);
        var j:longint;
        begin
            for j:=0 to 1 do
            begin
                x[i]:=j;
                //a[i]:=j;
                //if j=0 then sa:=sa+a[i] else sb:=sb+a[i];
                sa:=sa+j*a[i];
                if i=n then ktra else TienTe(i+1);
                sa:=sa-j*a[i];
            end;
        end;
        Begin
            readln(n); s:=0; sa:=0;  count:=0;
            for i:=1 to n do begin read(a[i]); s:=s+a[i]; end;
            TienTe(1);
            if count=0 then begin writeln('khong chia duoc'); exit; end;
            writeln(count);
            for i:=1 to count do writeln(ketqua[i]);
            readln;
        End.