import java.util.*; import java.io.*; public class help { public static void main(String args[]) throws IOException{ double a = 0.0; double b = 0.0; double rozdil = 0.0; while(true) { StringBuffer s = new StringBuffer(); BufferedReader bf= new BufferedReader(new InputStreamReader(System.in)); int pocet = Integer.parseInt(bf.readLine()); if(pocet == 0) { break; } else { String pom = bf.readLine(); StringTokenizer st = new StringTokenizer(pom," "); double [] pole = new double[pocet]; int i = 0; while (st.hasMoreTokens()) { pole[i] = Double.parseDouble(st.nextToken()); i++; } Arrays.sort(pole); a=0.0; b=0.0; rozdil =0; for(int j = 0;j < pole.length; j++) { rozdil = a-b; if(a=b){ b = pole[j]; s.append(pole[j] + "-B "); } } //System.out.print(s); } break; } } }