import java.math.*;
import java.util.*;
 
public class Main {
	static int dfs(int now){
		if(dp[now]!=0) return dp[now];
		int res=0;
		for(int i=0;i<n;i++){
			if(now-c[i]<0) continue;
			kai[i]++;
			res=Math.max(res,dfs(now-c[i])+(int)(v[i]/Math.pow(2,kai[i]-1)));
			kai[i]--;
		}
		return dp[now]=res;
	}
	static int[] kai;
	static int n;
	static int[] c;
	static int[] v;
	static int[] dp;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int t=sc.nextInt();
        n = sc.nextInt();
        dp=new int[t+1];
        c=new int[n];
        kai=new int[n];
        v=new int[n];
        for(int i=0;i<n;i++){
        	c[i]=sc.nextInt();
        }
        for(int i=0;i<n;i++){
        	v[i]=sc.nextInt();
        }
        System.out.println(dfs(t));
    }
}