use proconio::input;

fn main () {
    input! {
        mut n: u128,
    }
    let mut ans: Vec<char> = Vec::new();
    while n > 1 {
        if n & 1 == 1 {
            n -= 1;
            n /= 2;
            ans.push('A');
        }
        else {
            n -= 1;
            n /= 3;
            ans.push('B');
        }
    }
    let s = ans.iter()
        .rev()
        .map(|&c| c.to_string())
        .collect::<String>();
    println!("{}", s);
}