L = int(input())
N = int(input())
W = list(map(int, input().split()))
V = [1] * N
dp = [[0 for i in range(L+1)] for p in range(N+1)]

for i in range(N):
    for j in range(L):
        if j - W[i] + 1 < 0:
            dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j])
        else:
            dp[i+1][j+1] = max(dp[i][j+1], dp[i][j-W[i]+1]+V[i])

print(dp[N][L])