题目描述
Problem Statement
Given are a sequence A= {a_1,a_2,......a_N} of N positive even numbers, and an integer M.
Let a semi-common multiple of A be a positive integer X that satisfies the following condition for every $k (1 \leq k \leq N)$:
- There exists a non-negative integer p such that $X= a_k \times (p+0.5)$.
Find the number of semi-common multiples of A among the integers between 1 and M (inclusive).
Input
Input is given from Standard Input in the following format:
N M
a_1 a_2 ... a_N
Output
Print the number of semi-common multiples of A among the integers between 1 and M (inclusive).
Constraints
- $1 \leq N \leq 10^5$
- $1 \leq M \leq 10^9$
- $2 \leq a_i \leq 10^9$
- a_i is an even number.
- All values in input are integers.
Sample Input 1
2 50
6 10
Sample Output 1
2
- $15 = 6 \times 2.5$
- $15 = 10 \times 1.5$
- $45 = 6 \times 7.5$
- $45 = 10 \times 4.5$
Thus, 15 and 45 are semi-common multiples of A. There are no other semi-common multiples of A between 1 and 50, so the answer is 2.
Sample Input 2
3 100
14 22 40
Sample Output 2
0
The answer can be 0.
Sample Input 3
5 1000000000
6 6 2 6 2
Sample Output 3
166666667
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分