#![allow(non_snake_case, unused_imports)]
use proconio::{fastout, input, marker::*};

#[fastout]
fn main() {
    input! {
        mut N: usize,
    }

    let mut ans = vec![];

    while N != 1 {
        if (N - 1) % 2 == 0 {
            N = (N - 1) / 2;
            ans.push('A');
        } else {
            N = (N - 1) / 3;
            ans.push('B');
        }
    }

    ans.reverse();
    println!(
        "{}",
        ans.iter()
            .map(|x| x.to_string())
            .collect::<Vec<_>>()
            .join("")
    );
}