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 Python (3.4.3) (judge verdict: Accepted)

import sys
from functools import reduce

def gcd(a, b):
    while b:
        a, b = b, a % b
    return abs(a)

def lcm(a, b):
    return abs(a // gcd(a, b) * b)

def cnt_2(n):
    cnt = 0
    while n % 2 == 0:
        cnt += 1
        n //= 2
    return cnt

n, m, *a = map(int, sys.stdin.read().split())

def main():
    for i in range(n):
        a[i] //= 2

    cnt = cnt_2(a[0])
    for i in range(1, n):
        if cnt_2(a[i]) != cnt:
            return 0

    l = reduce(lcm, a, a[0])
    
    return m // l - m // (l * 2)

if __name__ == '__main__':
    ans = main()
    print(ans)