l = int(input())
n = int(input())
W = sorted(list(map(int, input().split())))

dp = [-1] * (l+1)
dp[0] = 0

for w in W:
    for i in range(l - 1, -1, -1):
      if i + w > l:
        continue
      elif dp[i] >= 0:
        dp[i + w] = max(dp[i] + 1, dp[i + w])

print(max(dp[:l - 1]) if l > 1 else dp[1])
#print(dp[:l - 1])