func main()
	var n: int :: cui@inputInt()
	
	var ans: bool :: true
	var cnt2: int :: 0
	var sum: int :: 0
	for i(0, n - 1)
		var a: int :: cui@inputInt()
		if(a > 2)
			do ans :: false
		end if
		if(a = 2)
			do cnt2 :+ 1
		end if
		do sum :+ a
	end for
	
	if(sum % 2 = 0)
		do ans :: false
	elif(cnt2 > 1)
		do ans :: false
	end if
	
	do cui@print(ans ?("A\n", "B\n"))
end func