import sys
#sys.setrecursionlimit(n)
import heapq
import re
import bisect
import random
import math
import itertools
from collections import defaultdict, deque
from copy import deepcopy
from decimal import *

t = int(input())
n = int(input())
ct = list(map(int, input().split()))
vt = list(map(int, input().split()))

dp = [0] * 20001
c = [0] * 2000
v = [0] * 2000
for i in range(n):
    c[i] = ct[i]
    v[i] = vt[i]
p = n
for i in range(n):
    j = c[i]
    k = v[i]
    while(1):
        k = k // 2
        if k == 0:
            break
        c[p] = j
        v[p] = k
        p += 1
for i in range(p):
    for j in reversed(range(t + 1 - c[i])):
        dp[j + c[i]] = max(dp[j + c[i]], dp[j] + v[i])
print(dp[t])