local ior = io.input()
local n = ior:read("*n")
local tot = 0
local b2 = 0
local b3 = false
for i = 1, n do
  local c = ior:read("*n")
  tot = tot + c
  if(c == 2) then b2 = b2 + 1
  elseif(3 <= c) then b3 = true end
end
if(tot % 2 == 0 or b3 or 2 <= b2) then print("B") else print("A") end