#include <iostream>
#include <vector>
#include <string>
#include <cstdio>
#include <algorithm>
using namespace std;
int main()
{
	vector<int> ceny;
	int count;

	int pom;
	bool a = false;
	while(1)
	{
		cin >> count;
		if(count<=0)
			break;
		ceny.clear();
		for(int i = 0; i<count; ++i)
		{
			cin >> pom;
			ceny.push_back(pom);
		}
		sort(ceny.begin(),ceny.end());
		
		cout << ceny.front() << "-A";
		while(ceny.size() > 1)
		{
			char znak = (a)?'A':'B';
			a=!a;
		
			//cout << " " << ceny.push_back() << "-" << string(znak);
			printf(" %d-%c",ceny.back(),znak);
			ceny.pop_back();
		}
		cout << "\n";
		a=false;
	}
	
	return 0;
}