#include <algorithm>
#include <iostream>

using namespace std;

int T, N;
int c[15], v[15];
int dp[10001];

int main() {
	cin >> T >> 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++) {
		for (int t = 0; t <= T; t++) {
			int vv = v[i];
			for (int j = 1; j * c[i] <= t && vv > 0; j++) {
				dp[t - j * c[i]] = max(dp[t - j * c[i]], dp[t - (j - 1) * c[i]] + vv);
				vv /= 2;
			}
		}
	}
	cout << dp[0] << endl;
	return 0;
}