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.
The first input line has two integers $n$ and $k$ .
The second line has $k$ prime numbers $a_1,a_2,\ldots,a_k$ .
Print one integer: the number integers within the interval $1,2,\ldots,n$ that are divisible by at least one of the prime numbers.
20 2 2 5
· \n · \n
12
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the $12$ numbers are $2,4,5,6,8,10,12,14,15,16,18,20$ .