#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int (i) = 0 ; (i) < (int)(n) ; (i)++)
#define REP(i,a,b) for(int (i) = a ; (int)(i) <= (int)(b) ; (i)++)
#define all(n) (n).begin(),(n).end()
typedef vector<int> Vi;
typedef vector<Vi> VVi;
typedef pair<long long,long long> Pii;
typedef vector<Pii> VPii;


vector<int> v,c;

int dp[10010];
int main(){
	int T;
	int N;
	cin >> T;
	cin >> N;
	rep(i,N){
		int C;
		cin >> C;
		rep(j,10) c.push_back(C);
	}
	rep(i,N){
		int V;
		cin >> V;
		rep(j,10){ v.push_back(V); V /= 2; }
	}
	for(int i = 0 ; i < v.size() ; i++){
		for(int j = 10000 ; j >= c[i] ; j--){
			dp[j] = max(dp[j],dp[j-c[i]] + v[i]);
		}
	}
	cout << dp[T] << endl;
	
}