import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


T = I()
N = I()
C = LI()
V = LI()

NC = []
NV = []
for i in range(N):
    c = C[i]
    v = V[i]
    while v:
        NC.append(c)
        NV.append(v)
        v //= 2

N = len(NC)

dp = [[0]*(T+1) for _ in range(N+1)]
for i in range(1,N+1):
    c = NC[i-1]
    v = NV[i-1]
    for j in range(T+1):
        if j >= c:
            dp[i][j] = max(dp[i-1][j],dp[i-1][j-c]+v)
        else:
            dp[i][j] = dp[i-1][j]

print(dp[-1][-1])