// includes
#include <cassert>
#include <cstdio>
#include <cstdint>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <string>
#include <queue>
#include <stack>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <utility>
#include <functional>
#include <cmath>
#include <climits>
#include <bitset>
#include <list>
#include <random>

// macros
#define ll long long int
#define pb emplace_back
#define mk make_pair
#define pq priority_queue
#define FOR(i, a, b) for(int i=(a);i<(b);++i)
#define rep(i, n) FOR(i, 0, n)
#define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--)
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end())

using namespace std;

//  types
typedef pair<int, int> P;
typedef pair<ll, int> Pl;
typedef pair<ll, ll> Pll;
typedef pair<double, double> Pd;
 
// constants
const int inf = 1e9;
const ll linf = 1LL << 50;
const double EPS = 1e-10;
const int mod = 1e9 + 7;

// solve
template <class T>bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;}
template <class T>bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;}

int va[10][16];
int dp[16][10001];

int main(int argc, char const* argv[])
{
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int t, n;
  cin >> t >> n;
  vector<int> c(n), v(n);
  rep(i, n)cin >> c[i];
  rep(i, n)cin >> v[i];
  rep(i, n){
    va[1][i] = v[i];
    for(int j = 2; j < 10; j++){
      va[j][i] = va[j-1][i] / 2;
    }
    for(int j = 2; j < 10; j++){
      va[j][i] += va[j-1][i];
    }
  }
  rep(i, t + 1){
    dp[0][i] = 0;
  }

  rep(i, n){
    rep(j, t+1){
      dp[i+1][j] = dp[i][j];
      FOR(k, 1, 10){
        if(j-k*c[i] < 0)break;
        dp[i+1][j] = max(dp[i+1][j], dp[i][j-k*c[i]] + va[k][i]);
      }
    }
  }

  cout << dp[n][t] << endl;
	return 0;
}