某对分查找算法的VB程序段如下所示: key = Val(Text1.Text) s= "" : i = 1: j = 10 Do Whilei <= j m = (i+j) \2 If a(m) = key Then Exit Do ‘Exit Do意退出循环 If key < a(m)Then j = m-1 : s = s+"L" Else i= m + 1 : s= s + "R" End If Loop 按非降序排序的整型数组a(1)到a(10)的值依次为“11,23,31,39,44,52,60,x,69,89”。在文本框Textl中输入66,执行该程序段后s值为“RLRL”,则x的可能值的个数为( )