n,m = map(int,input().split())
a = set(map(int,input().split()))

def divisors(N):
    #Nの約数列挙
    divisors = []
    for i in range(1, N + 1):
        if i * i > N:
            break
        if N % i == 0:
            divisors.append(i)
            if N != i * i:
                divisors.append(N // i)
    return divisors

savotaged = [0]*(n+1)
ans = 0
for i in range(n-1,-1,-1):
    cnt = n//(i+1)
    if(cnt + savotaged[i+1])%2==0:
        if(i+1 in a):
            ans+=1
            for num in divisors(i+1):
                savotaged[num]^=1
        else:
            continue
    else:
        if(i+1 in a):
            continue
        else:
            ans+=1
            for num in divisors(i+1):
                savotaged[num]^=1

print(ans)