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

int main() {
    int N, T, C[20], V[20];
    cin >> T >> N;
    for (int i = 0; i < N; i++) {
        cin >> C[i];
    }
    for (int i = 0; i < N; i++) {
        cin >> V[i];
    }

    int dp[10010] = {};
    for (int i = 0; i < N; i++) {
        for (int t = T; t >= 0; t--) {
            int c = C[i], v = V[i], sum = 0;
            for (int times = 1; times < 10; times++) {
                int nxt_t = t + times * c;
                sum += v;
                if (nxt_t <= T) {
                    dp[nxt_t] = max(dp[nxt_t], dp[t] + sum);
                }
                v >>= 1;
            }
        }
    }
    cout << dp[T] << endl;
}