#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <tuple>
#include <iomanip>
using namespace std;

#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define uniq(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef pair<int, int> P;
typedef unsigned int uint;
typedef unsigned long long ull;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};

const int inf = 1000000009;
const double eps = 1e-8;

void add(int c, int v, vector<P>& vec) {
    int n = 1;
    int sum = v;
    while (v > 0) {
	vec.push_back(make_pair(n * c, sum));
	n++;
	v /= 2;
	sum += v;
    }
}

int solve(int t, int n) {
    vector<P> vec[16];
    int c[n], v[n];
    for (int i = 0; i < n; i++) scanf("%d", &c[i]);
    for (int i = 0; i < n; i++) scanf("%d", &v[i]);
    for (int i = 0; i < n; i++) {
	add(c[i], v[i], vec[i]);
    }

    int dp[t+1];
    memset(dp, 0, sizeof(dp));
    for (int i = 0; i < n; i++) {
	vector<P>& cv = vec[i];
	for (int j = t; j >= 0; j--) {
	    for (int k = 0; k < cv.size(); k++) {
		if (j + cv[k].first <= t)
		    dp[j+cv[k].first] = max(dp[j+cv[k].first], dp[j] + cv[k].second);
	    }
	}
    }
    return dp[t];
}

int main() {
    /*
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);
    */
    int t, n;
    scanf("%d%d", &t, &n);
    printf("%d\n", solve(t, n));
}