public static void sort ( String prefix, String [] a ) {
	out = "";
	if ( a.length == 1 ) {
            out = prefix + a[0];
	    if ( isDiv(out)  ) {
		data.add(out);
	    }
	}
	for ( int i=0, limit=a.length; i<limit; i++ ) {
	    b = new String[a.length-1];
	    System.arraycopy(a,0,b,0,i);
	    System.arraycopy(a,i+1,b,i,a.length-i-1);
	    sort(prefix+a[i], b);
	}
    }