#include <iostream>
#include <vector>

using namespace std;


int main() {
    while(cin) {
	int N;
	cin >> N;
	
	if (N==0) return 0;
	vector<int> vect;
	for (int i=0; i < N; i++) {
	    int x;
	    cin >> x;
	    vect.push_back(x);
	}
	
	sort(vect.begin(), vect.end());
	
	
	char pismeno = 'A';
	cout << vect[0] << "-" << pismeno;
	vect.erase(vect.begin());
	pismeno='B';
	while (vect.size()) {
	    int i=vect.back();
	    vect.pop_back();
	    cout << " " <<  i << "-" << pismeno;
	    if (pismeno=='A') pismeno='B'; else pismeno='A';
//	    vect.erase(vect.end());
	}
	cout << endl;
    }
    
    return 0;
}