#include <bits/stdc++.h>
using namespace std;
#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repl(i,0,n)
#define mp(a,b) make_pair((a),(b))
#define pb(a) push_back((a))
#define all(x) (x).begin(),(x).end()
#define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x))
#define fi first
#define se second
#define dbg(x) cout<<#x" = "<<((x))<<endl
template<class T,class U> ostream& operator<<(ostream& o, const pair<T,U> &p){o<<"("<<p.fi<<","<<p.se<<")";return o;}
template<class T> ostream& operator<<(ostream& o, const vector<T> &v){o<<"[";for(T t:v){o<<t<<",";}o<<"]";return o;}

#define INF 2147483600

int main(){
  int t,n;
  cin>>t>>n;
  vector<int> c(n), v(n);
  rep(i,n) cin>>c[i];
  rep(i,n) cin>>v[i];

  vector<vector<int>> dp(11, vector<int>(t+1, -INF));
  dp[0][0] = 0;
  rep(i,n){
    for(int j=0; v[i]>0; j++,v[i]/=2){
      rep(k,t) if(dp[j][k]>=0){
        if(k+c[i] <= t) dp[j+1][k+c[i]] = max(dp[j+1][k+c[i]], dp[j][k] + v[i]);
      }
    }
//    rep(j,10)dbg(dp[j]);
    rep(j,t+1) repl(k,1,11){
      dp[0][j] = max(dp[0][j], dp[k][j]);
      dp[k][j] = -INF;
    }
  }

  cout << *max_element(all(dp[0])) << endl;

  return 0;
}