interface Comparable<A> {
  public int compareTo(A that);
}

class Byte implements Comparable<Byte> {
  private byte value;
  public Byte(byte value){ this.value = value; }
  public byte byteValue(){ return value; }
  public int compareTo(Byte that){
    return this.value - that.value;
  }
}

class Collections {
  public static <A extends Comparable<A>> A max(Collection<A> xs){
    Iterator<A> xi = xs.iterator();
    A w = xi.next();
    while(xi.hasNext()){
      A x = xi.next();
      if(w.compareTo(x) < 0) w = x;
    }
    return w;
  }
}