If an integer, with the three numbers 1, 2, and 3, can make the result equal to 24 through addition, subtraction, multiplication, and division operations (you can add parentheses), then this integer is called usable. Among the ten numbers 4, 7, 9, 11, 17, 20, 22, 25, 31, 34, how many numbers are available?
如果一个整数，与l，2，3这三个数，通过加、减、乘、除运算(可以添加括号)组成算式，能使结果等于24，那么这个整数就称为可用的．在4，7，9，11，17，20，22，25，31，34这十个数中，可用的数有多少个．
<result>9</result>