- Time limit: 1.00 s
- Memory limit: 512 MB
You are given k distinct prime numbers a_1,a_2,\ldots,a_k and an integer n.
Your task is to calculate how many of the first n positive integers are divisible by at least one of the given prime numbers.
Input
The first input line has two integers n and k.
The second line has k prime numbers a_1,a_2,\ldots,a_k.
Output
Print one integer: the number integers within the interval 1,2,\ldots,n that are divisible by at least one of the prime numbers.
Constraints
- 1 \le n \le 10^{18}
- 1 \le k \le 20
- 2 \le a_i \le n
Example
Input:
20 2 2 5
Output:
12
Explanation: the 12 numbers are 2,4,5,6,8,10,12,14,15,16,18,20.