#include <iostream>
#include <list>

using namespace std;


list<int> numbers;

bool readList()
{
	int n;
	cin >> n;
	if (n == 0) return false;
	while (n-->0)
	{
		int num;
		cin >> num;
		numbers.push_back(num);
	}
	return true;
}


int main()
{
	while(readList())
	{
		numbers.sort();
		char bank = 'A';
		cout << numbers.front() << '-' << bank;
		numbers.pop_front();
		while (!numbers.empty())
		{
			bank = (bank == 'A') ? 'B' : 'A';
			cout << " " << numbers.back() << "-" << bank;
			numbers.pop_back();
		}
		cout << endl;
	}	
	return 0;
}