class osa_k:
    min_factor = []
    def __init__(self, n):
        self.min_factor = list(range(n + 1))
        i = 2
        while i * i <= n:
            if self.min_factor[i] < i:
                i += 1
                continue
            for j in range(i*i, n + 1, i):
                if self.min_factor[j] == j:
                    self.min_factor[j] = i
            i += 1

    def factor(self, n):
        res = []
        while n > 1:
            res.append(self.min_factor[n])
            n //= self.min_factor[n]
        return res

    def divisors(self, n):
        res = [1]
        while n > 1:
            x = self.min_factor[n]
            cnt = 0
            while n % x == 0:
                cnt += 1
                n //= x
            t = []
            p = 1
            for i in range(cnt + 1):
                for j in range(len(res)):
                    t.append(res[j] * p)
                p *= x
            res = t[:]
        return res

osk = osa_k(200000)

n, m = map(int, input().split())
d = [0] * (n + 1)
d2 = [0] * (n + 1)
a = list(map(int, input().split()))
for x in a:
    d2[x] = 1
for i in range(1, n + 1):
    d[i] = (n // i) % 2
ans = 0
for i in range(n, 0, -1):
    if d[i] != d2[i]:
        ans += 1
        for dv in osk.divisors(i):
            d[dv] ^= 1
print(ans)