def prime(n): 
    l = [2, 3]
    if n < 5 : return l 
    for i in range(5, n+1, 2):
        if all([0 if i % x == 0 else 1 for x in l]):
            l += [i]
    return l

M = int(input())
N = int(input())
C = list(map(int, input().split()))
p = set(prime(M))
ans = M // min(C)
q = [0]
cnt = 0
d = {}
while q:
    cnt += 1
    l = []
    for i in set(q):
        for j in C:
            a = i + j
            if a <= M:
                 l += [a]
                 if M - a in p:
                    d[M - a] = cnt
    q = l
for i in d.values():
    ans += i
print(ans)