Prime Multiples

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