题目描述
Problem Statement
There are $N integers A_1, A_2, A_3, \dots, A_N written on a$ blackboard.
You will do the following operation N - 1 times:
- Choose two numbers written on the blackboard and erase them. Let x and y be the erased numbers. Then, write $\gcd(x, y)$ or $\min(x, y)$ on the blackboard.
After N - 1 operations, just one integer will remain on the blackboard. How many possible values of this number are there?
Input
Input is given from Standard Input in the following format:
N
$A_1 A_2 A_3 \dots A_N$
Output
Print the number of possible values of the last remaining number on the blackboard.
Constraints
- $2 \le N \le 2000$
- $1 \le A_i \le 10^9$
- All values in input are integers.
Sample Input 1
3
6 9 12
Sample Output 1
2
The possible values of the last remaining number are 3 and 6.
We will have 3 in the end if, for example, we do as follows:
- choose 9, 12 and erase them from the blackboard, then write $\gcd(9, 12) = 3$;
- choose 6, 3 and erase them from the blackboard, then write $\min(6, 3) = 3$.
Also, we will have 6 in the end if, for example, we do as follows:
- choose 6, 12 and erase them from the blackboard, then write $\gcd(6, 12) = 6$;
- choose 6, 9 and erase them from the blackboard, then write $\min(6, 9) = 6$.
Sample Input 2
4
8 2 12 6
Sample Output 2
1
2 is the only number that can remain on the blackboard.
Sample Input 3
7
30 28 33 49 27 37 48
Sample Output 3
7
1, 2, 3, 4, 6, 7, and 27 can remain on the blackboard.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分