#描述#
he following cryptarithm is a multiplication problem that can be solved by substituting digits from a specified set of N digits into the positions marked with *. If the set of prime digits {2,3,5,7} is selected, the cryptarithm is called a PRIME CRYPTARITHM.

* * *
x * *
-------
* * *
* * *
-------
* * * *

Digits can appear only in places marked by `*'. Of course, leading zeroes are not allowed.
Write a program that will find all solutions to the cryptarithm above for any subset of digits from the set {1,2,3,4,5,6,7,8,9}.

#格式#
##输入格式##
There are more than one case.Each case contains:
Line 1: N, the number of digits that will be used .N=0 means the end of input.
Line 2: N space separated digits with which to solve the cryptarithm

##输出格式##
A single line with the total number of unique solutions. Here is the solution for the sample input:

2 2 2
x 2 2
------
4 4 4
4 4 4

---

4 8 8 4

#样例1#
##样例输入1##

5
2 3 4 6 8

##样例输出1##

1

#限制#
1000ms
32768KB

#提示#

#来源#