T=int(input())
N=int(input())
C=list(map(int,input().split()))
V=list(map(int,input().split()))

DP=[0]*(10**6)
for i in range(T+1):
    DP[i]=max(DP[i-1],DP[i])

    for j in range(N):
        c=C[j]
        v=V[j]

        DP[i+c]=max(DP[i+c],DP[i]+v)

DP={0:0}

for i in range(N):
    c=C[i]
    v=V[i]

    x=v
    s=v
    time=c
    L=[]
    while x!=0:
        for k in DP:
            if k+time<=T:
                L.append((k+time,DP[k]+s))
        x//=2
        s+=x
        time+=c

    for time,v in L:
        if time in DP:
            DP[time]=max(DP[time],v)
        else:
            DP[time]=v

print(max(DP.values()))