#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cmath>
#include <queue>
#include <stack>

#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
#define MAX 20
#define NUM 20000
typedef long long ll;

using namespace std;


int inputValue(){
    int a;
    cin >> a;
    return a;
};

void inputArray(int * p, int a){
    rep(i, a){
        cin >> p[i];
    }
};

void inputVector(vector<int> * p, int a){
    rep(i, a){
        int input;
        cin >> input;
        p -> push_back(input);
    }
}

template <typename T>
void output(T a, int precision) {
    if(precision > 0){
        cout << setprecision(precision)  << a << "\n";
    }
    else{
        cout << a << "\n";
    }
}
int dp[NUM];

int main(int argc, const char * argv[]) {
    
    // source code
    int T = inputValue();
    int N = inputValue();
    vector<int> c;
    vector<int> v;
    
    
    rep(i, N){
        c.push_back(inputValue());
    }
    rep(i, N){
        v.push_back(inputValue());
    }
    
    rep(i, N){
        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 ret = 0;
    rep(i, T + 1){
        ret = max(ret, dp[i]);
    }
    
    output(ret, 0);
    
    return 0;
}