def dfs(arr, N):
  # print(N)
  if N==1:
    for i in range(len(arr)-1, -1, -1):
      print(arr[i],end="")
    print()
    exit()
  if N%2==1:
    new_arr = arr[:]
    new_arr.append("A")
    dfs(new_arr, (N-1)//2)
  if N%3==1:
    new_arr = arr[:]
    new_arr.append("B")
    dfs(new_arr, (N-1)//3)

_N=int(input())

dfs([], _N)