#include<iostream>
#include<vector>
#include<cstdio>
#include<string>

using namespace std;
int balikov, temp, A;
vector <int> baliky;

int main()
{
	while (true)
	{
		cin >> balikov;
		if (balikov == 0) return 0;
		baliky.clear();
		while (balikov--)
		{
			cin >> temp;
			baliky.push_back(temp);
		}
		sort(baliky.begin(), baliky.end());
		cout << baliky[0] << "-A";
		A = 0;
		for (int i = baliky.size()-1; i>0; i--)
		{
			cout << " " << baliky[i] << "-" << (A?"A":"B");
			A = !A;
		}
		cout << endl;
	}
	return 0;
}