Problem:
Score : 400 points

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).

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.

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).

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

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<algorithm>
using namespace::std;
#define int long long int

int ar[200005];

main(){
	int n,m;
	cin>>n>>m;
	for(int i=0;i<n;i++)
		cin>>ar[i];
	int t=1;
	for(int i=0;i<n;i++)
		if(2*m/ar[i]>=t/__gcd(ar[i]/2,t))
			t=ar[i]/2/__gcd(ar[i]/2,t)*t;
		else{
			cout<<0<<'\n';
			return 0;
		}
	int lcm=1;
	for(int i=0;i<n;i++)
		if(m/ar[i]>=lcm/__gcd(ar[i],lcm))
			lcm*=ar[i]/__gcd(ar[i],lcm);
		else{
			lcm=1e18;
		}
	
	cout<<(m-t)/t/2+1<<'\n';//<<t<<' '<<lcm<<'\n';
}