import os, sys
import math, decimal, queue, heapq, bisect, itertools, functools, collections, string
from bisect import bisect, bisect_left
from collections import defaultdict, OrderedDict, deque, Counter
from functools import cmp_to_key, lru_cache, reduce
from heapq import heapify, heappush, heappushpop, heappop, heapreplace, nlargest, nsmallest
from itertools import accumulate, chain, combinations, combinations_with_replacement, compress, count, cycle, dropwhile, filterfalse, groupby, islice, permutations, product, repeat, starmap, takewhile, tee, zip_longest
from math import gcd, factorial, isqrt, comb, perm, prod, inf
from queue import Queue, PriorityQueue, LifoQueue
from string import ascii_letters, ascii_lowercase, ascii_uppercase, digits, hexdigits, octdigits

LOCAL = sys.argv[0] if '4a' in sys.argv[0] else None

P = lambda *p: [print(i) for i in p] if LOCAL else None
PI = lambda *p: print(' '.join(map(str, p))) or None
PII = lambda X: [PI(*row) for row in X]

sys.stdin = open(os.path.join(os.getcwd(), 'a3.txt'), 'r') if LOCAL else sys.stdin
I = lambda: [int(a) for l in sys.stdin for a in l.strip().split()]
S = lambda: [a for l in sys.stdin for a in l.strip().split()]
IM = lambda: [[int(a) for a in l.split()] for l in sys.stdin]
SM = lambda: [[a for a in l.split()] for l in sys.stdin]

az, AZ, mod = ascii_lowercase, ascii_uppercase, 1_000_000_007

A = I()
P(A)


def solution(A):
    def sol(x, y, res=''):
        if x < 3:
            return res
        if x >= 3 and (x - 1) % 2 == 0:
            x -= 1
            x //= 2
            res += 'A'
        if x >= 4 and (x - 1) % 3 == 0:
            x -= 1
            x //= 3
            res += 'B'
        # try:
        return sol(x, y, res)
        # except:
        # return ''

    x, y = A[0], A[0]
    ans = sol(x, y, '')
    print(ans[::-1])


solution(A)