N=int(input())
def dfs(arr, n):
  if n==N:
    print("".join(arr))
    exit()
  elif n>N:
    return
  newArr = arr[:]
  newArr.append("A")
  dfs(newArr, 2*n+1)

  newArr = arr[:]
  newArr.append("B")
  dfs(newArr, 3*n+1)

dfs([], 1)