#include<bits/stdc++.h>
using namespace std;
#define inf INT_MAX
#define INF LLONG_MAX
#define ll long long
#define ull unsigned long long
#define M (int)(1e9+7)
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(a,n) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265
#define F first
#define S second
#define PB push_back
#define EB emplace_back
#define int ll
#define vi vector<int>
#define PD pair<double,int>


signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int t,n;
  cin>>t>>n;
  vi c(n),v(n);
  rep(i,n){
    cin>>c[i];
  }
  rep(i,n){
    cin>>v[i];
  }

  int dp[11000]={};

  rep(k,10){
    rep(i,n){
      RFOR(j,t,c[i]){
        dp[j]=max(dp[j],dp[j-c[i]]+v[i]);
      }
      v[i]/=2;
    }
  }

  int ans=0;
  rep(i,t+1){
    ans=max(ans,dp[i]);
  }

  cout<<ans<<endl;

}