import java.util.*;
public class manyball{
    public static String findS(String ans,long num){
        
        if(num==0){
            return ans;
        }    
        if(num%2==0){
            num/=2;
            ans = findS(ans, num)+"B";
        }else{
            num-=1;
            ans = findS(ans, num)+"A";
        }
        return ans;
    }
    public static void main (String[] args){
        Scanner in = new Scanner(System.in);
        long  num = in.nextLong();
        String ans = "";
        System.out.println(findS(ans, num));
    }
}