#define _CRT_SECURE_NO_WARNINGS
#include<sstream>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<cmath>
#include<string>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<numeric>
#include<functional>
#include<algorithm>
#include<bitset>
#include<tuple>
#include<unordered_set>
#include<random>
using namespace std;
#define INF (1<<29)
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define uniq(v) v.erase(unique(all(v)),v.end())
#define indexOf(v,x) (find(all(v),x)-v.begin())


int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int t,n,c[15],v[15];
	cin>>t>>n;
	vector<int> dp(t+1,0);
	rep(i,n)cin>>c[i];
	rep(i,n)cin>>v[i];
	rep(i,n){
		int a=v[i];
		while(a){
			for(int j=t-c[i];j>=0;j--){
				dp[j+c[i]]=max(dp[j+c[i]],dp[j]+a);
			}
			a/=2;
		}
	}
	cout<<*max_element(all(dp))<<endl;
	return 0;
}