from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

M = int(input())
N = int(input())
C = list(map(int,input().split()))
class prime_factorize():
    
    def __init__(self,M=10**6):
        self.sieve = [-1]*(M+1)
        self.sieve[1] = 1
        self.p = [False]*(M+1)
        self.mu = [1]*(M+1)
        
        for i in range(2,M+1):
            if self.sieve[i] == -1:
                self.p[i] = True
                
                i2 = i**2
                for j in range(i2,M+1,i2):
                    
                    self.mu[j] = 0
                
                
                for j in range(i,M+1,i):
                    self.sieve[j] = i
                    
                    self.mu[j] *= -1
                    
    def factors(self,x):
        tmp = []
        while self.sieve[x] != x:
            tmp.append(self.sieve[x])
            x //= self.sieve[x]
        tmp.append(self.sieve[x])
        return tmp
        
    def is_prime(self,x):
        return self.p[x]
        
    def mobius(self,x):
        return self.mu[x]
        
pf = prime_factorize()

dp = [-1]*(M+1)
dp[0]=0
for i in range(N):
    c = C[i]
    if c>M:
        continue
    if dp[c]==-1:
        dp[c]=1
    for j in range(M+1-c):
        
        if dp[j]!=-1:
            
            dp[j+c]=max(dp[j+c],dp[j]+1)
            
# for i in range(M+1):
#     if dp[i]!=-1:
#         print(i,dp[i])
ans = sum(dp[i]*pf.is_prime(M-i)*(dp[i]!=-1) for i in range(M+1)) + max(dp[i] for i in range(M+1))
print(ans)