def main():
    import sys
    input = sys.stdin.read().split()
    idx = 0
    N = int(input[idx])
    idx += 1
    M = int(input[idx])
    idx += 1
    A = list(map(int, input[idx:idx+M]))
    A_set = set(A)
    
    in_S = [False] * (N + 2)  # 1-based indexing
    
    for j in range(N, 0, -1):
        desired = 1 if j in A_set else 0
        s = 0
        k = 2 * j
        while k <= N:
            if in_S[k]:
                s += 1
            k += j
        x = (desired - s) % 2
        if x == 1:
            in_S[j] = True
    
    count = sum(in_S)
    print(N - count)

if __name__ == '__main__':
    main()