M,N= int(input()),int(input())
C = sorted([int(i) for i in input().split()])
prime = [True for i in range(M + 1)]
prime[0] = prime[1] = False
dp = [-1 for i in range(M + 1)]
for i in range(2,M + 1):
	if prime[i]:
		j = 2
		while i * j <= M:
			prime[i * j] = False
			j+=1
dp[M] = 0
for i in range(N):
	for j in range(M,-1,-1):
		if dp[j] != -1 and j - C[i] >= 0:
			dp[j - C[i]] = max(dp[j - C[i]],dp[j] + 1)
ans = 0
for i in range(M + 1):
	if prime[i] and dp[i] >= 0:
		ans += dp[i]
ans += M // C[0]
print(ans)