def oi(): return int(input())
def os(): return input()
def mi(): return list(map(int, input().split()))

def make_divisors(n):
    divisors = []
    for i in range(1, int(n**0.5)+1):
        if n % i == 0:
            divisors.append(i)
            if i != n // i:
                divisors.append(n//i)

    # divisors.sort()
    return divisors

input_count = 0
N, M = mi()
A = mi()
NA = [1]*N

C = []
for i in range(1,N+1):
    if (N//i)%2==0:
        C.append(1)
    else:
        C.append(-1)

for a in A:
    NA[a-1] = -1

hoge = []
for c, nn in zip(C, NA):
    if c!=nn:
        hoge.append(1)
    else:
        hoge.append(0)

count = 0
for i in range(N-1, -1, -1):
    if hoge[i]==1:
        count += 1
        for j in make_divisors(i+1):
            if hoge[j-1] == 0:
                hoge[j-1] = 1
            else:
                hoge[j-1] = 0

print(count)