t = int(input())
n = int(input())
c = list(map(int, input().split()))
v = list(map(int, input().split()))
for i in range(n):
    x = v[i] // 2
    while x > 0:
        c.append(c[i])
        v.append(x)
        x //= 2
m = len(c)
dp = [[-float('inf')] * (t + 1) for _ in range(m + 1)]
dp[0][0] = 0
for i in range(m):
    for j in range(t + 1):
        dp[i + 1][j] = max(dp[i + 1][j], dp[i][j])
        if j + c[i] <= t:
            dp[i + 1][j + c[i]] = max(dp[i + 1][j + c[i]], dp[i][j] + v[i])
print(max(dp[-1]))