#!/usr/bin/env python3
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


# %%
N = int(read())

# %%
dp = [0] * 101
dp[2] = 1
for n in range(3, 101):
    G = []
    q, r = divmod(n, 2)
    if r == 0:
        G.append(0)
    else:
        G.append(dp[q] ^ dp[q + 1])
    q, r = divmod(n, 3)
    if r == 0:
        G.append(dp[q])
    elif r == 1:
        G.append(dp[q + 1])
    else:
        G.append(dp[q])
    g = 0
    while True:
        if g in G:
            g += 1
            continue
        dp[n] = g
        break


# %%
answer = 'A' if dp[N] else 'B'
print(answer)