#include<bits/stdc++.h>
using namespace std;
#define int long long
int n;
string ans;
bool ok;
void dfs(int x,string s)
{
	if(x<0)return;
	if(x==0)
	{
		reverse(s.begin(),s.end());
		cout<<s<<'\n';
		ok=1;
		return;
	}
	if(x%2==0)
	{
		dfs(x/2,s+'B');
		if(ok)return;
	}
	dfs(x-1,s+'A');
}
signed main()
{
	cin>>n;
	dfs(n,"");
	return 0;
}