#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>

using namespace std;

#define loop(i,a,b) for(int i=(a);i<int(b);i++)
#define rep(i,b) loop(i,0,b)

typedef long long ll;

int T;
int N;
int c[16];
int v[16];

int dp[20000];

int main(){
    memset(dp, 0, sizeof(dp));
    cin >> T >> N;
    rep(i, N)cin >> c[i];
    rep(i, N)cin >> v[i];
    vector<int> v_;
    vector<int> w_;
    rep(i, N){
        rep(j, 10){
            if (v[i] >> j){
                v_.push_back(v[i] >> j);
                w_.push_back(c[i]);
            }
            else {
                break;
            }
        }
    }
    
    rep(i, v_.size()){
        for (int j = T; j >= 0; j--){
            if (j - w_[i] >= 0)dp[j] = max(dp[j - w_[i]] + v_[i], dp[j]);
        }
    }
    cout << dp[T] << endl;
}