#include "bits/stdc++.h"
using namespace std;

#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)

int T, N;
struct A { int c, v; };
vector<A> a;

int main()
{
    cin>>T>>N;
    REP(i,N) {
        A ai = A();
        cin >> ai.c;
        a.push_back(ai);
    }
    REP(i,N) cin >> a[i].v;
    int dp[20001] = {0};
    REP(i,N) {
        A ai = a[i];
        int v = ai.v;
        int c = ai.c;
        while(v > 0) {
            RREP(j,10001) {
                dp[j+c] = max(dp[j+c], dp[j] + v);
            }
            v /= 2;
        }
    }
    cout << dp[T] << endl;
    return 0;
}