#include <stdio.h>
#include <stdlib.h>
#define N 50010
int mon[N];
typedef int * ip;
int cmp(const void * a, const void * b){
	return ((*(ip(a)))<=(*(ip(b))))*(-1) + ((*(ip(a)))>(*(ip(b))));
}
int main(){
	int n,i; char w[2];
	while(1){
		scanf("%d",&n);
		if(n==0)return 0;

		for(i=0;i<n;i++){
			scanf("%d",&mon[i]);
		}
		qsort(mon,n,sizeof(int),cmp);

		printf("%d-A",mon[0]);
		if((n-1)%2)w[1]='B', w[0]='A';
		else w[1]='A', w[0]='B';
		for(i=n-1;i>0;i--){
			printf(" %d-%c",mon[i],w[i%2]);
		}
		printf("\n");
	}
}