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

int dp[20000];

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