# coding: utf-8

import numpy as np

L = int(input())
N = int(input())
length = [int(i) for i in input().split()]

dp = -1*np.ones((N+1,L+1))

for l in range(L+1):
    dp[N][l] = 0

i = N - 1
while i > -1:
    for l in range(L+1):
        if l < length[i]:
            dp[i][l] = dp[i+1][l]
        else:
            dp[i][l] = max(dp[i+1][l], dp[i+1][l - length[i]] + 1)
    i = i - 1

print(int(dp[0][L]))