import sys import math import bisect from heapq import heapify, heappop, heappush from collections import deque, defaultdict, Counter from functools import lru_cache from itertools import accumulate, combinations, permutations, product sys.setrecursionlimit(1000000) MOD = 10 ** 9 + 7 MOD99 = 998244353 input = lambda: sys.stdin.readline().strip() NI = lambda: int(input()) NMI = lambda: map(int, input().split()) NLI = lambda: list(NMI()) SI = lambda: input() SMI = lambda: input().split() SLI = lambda: list(SMI()) EI = lambda m: [NLI() for _ in range(m)] def main(): T = NI() N = NI() C = NLI() V = NLI() CV = [] for c, v in zip(C, V): while v > 0: CV.append([c, v]) v //= 2 N = len(CV) dp = [[0]*(T+1) for _ in range(N+1)] for i in range(N): c, v = CV[i] for j in range(T+1): dp[i+1][j] = max(dp[i+1][j], dp[i][j]) if j+c <= T: dp[i+1][j+c] = max(dp[i+1][j+c], dp[i][j]+v) print(max(dp[-1])) if __name__ == "__main__": main()