#include <iostream>
#include <cstdio>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <utility>
#include <sstream>
using namespace std;

#define FOR(i,n) for (int i=0; i<int(n); i++)
//#define FOR(i,a,n) for (int i=a; i<int(n); i++)
#define FORD(i,n) for (int i=int(n)-1; i>=0; i--)
#define pb push_back
#define fi first
#define se second

typedef long long ll;
typedef pair<int, int> pi;

int data[100000];

int main()
{
    int N;
    while (true) {
    scanf("%d",&N);
    if (N==0) break;
    FOR(q,N) scanf("%d",&data[q]);
    sort(data,data+N);
    printf("%d-A",data[0]);
    int i=0;
    for(int q=N-1; q>0; q--) {
	i^=1;
	printf(" %d-%c",data[q],(i==0)?'A':'B');
    }
    printf("\n");




    }
}