#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>

#define INF 100000000
#define EPS 1e-9

using namespace std;

typedef pair<int, int> P;
typedef long long ll;

#define MAX_T 10000
#define MAX_N 15
int T, N;
int c[MAX_N];
int v[MAX_N];

int dp[MAX_N+1][MAX_T + 1];

int les(int s, int m){
	if (m == 0)
		return 0;
	int ans = s / (pow(2, m - 1)) + les(s, m-1);
	return ans;
}

int main() {

	cin >> T;
	cin >> N;
	for (int i = 0; i < N; i++){
		cin >> c[i];
	}
	for (int i = 0; i < N; i++){
		cin >> v[i];
	}

	int ans = 0;

	for (int i = 0; i < N; i++){
		for (int j = 0; j <= T; j++){
			for (int m = 0; j - m*c[i] >= 0; m++){
				dp[i + 1][j] = max(dp[i + 1][j], dp[i][j - m*c[i]] + les(v[i], m));
				ans = max(ans, dp[i + 1][j]);
			}
		}
	}
	
	cout << ans << endl;

	return 0;
}