#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <string>
#include <numeric>
#include <cstring>
#include <cmath>
#include <set>
#include <queue>
#include <stack>

const int MOD = 1e9 + 7;
const int iINF = 1000000000;
const long long int llINF = 1000000000000000000;
#define rep(i, n) for (int i = 0; i < (n); i++)

using namespace std;
using ll = long long int;
using P = pair<int, int>;
using edge = struct
{
    int to;
    int cost;
};

int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int T, N;
int dp[20000];

int main()
{
    cin >> T >> N;
    vector<int> c(N), v(N);
    rep(i, N) cin >> c[i];
    rep(i, N) cin >> v[i];

    for (int i = 0; i < N; i++)
    {
        while (v[i] > 0)
        {
            for (int j = T; 0 <= j; j--)
            {
                dp[j + c[i]] = max(dp[j + c[i]], dp[j] + v[i]);
            }
            v[i] /= 2;
        }
    }
    int ans = 0;
    rep(i, T + 1) ans = max(ans, dp[i]);

    cout << ans << endl;
    return 0;
}