m=int(input())
n=int(input())
a=list(map(int,input().split()))
dp=[-1]*(m+1);dp[0]=0
for i in range(m):
    if dp[i]<0:
        continue
    for j in a:
        if i+j<=m:
            dp[i+j]=max(dp[i+j],dp[i]+1)
x=[0]*m;ans=max(dp)
for i in range(2,m):
    if x[i]:
        continue
    for j in range(i,m,i):
        x[j]=1
    ans+=max(0,dp[m-i])
print(ans)