package no037;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int t = sc.nextInt();
		int n = sc.nextInt();
		int[] c = new int[n];
		int[] v = new int[n];
		int[][] v2 = new int[n][10];
		for(int i=0;i<n;i++) {
			c[i] = sc.nextInt();
		}
		for(int i=0;i<n;i++) {
			v[i] = sc.nextInt();
		}
		for(int i=0;i<n;i++) {
			for(int j=1;j<10;j++) {
				v2[i][j] = v2[i][j-1] + (v[i] >> (j-1));
			}
		}
//		System.out.println(Arrays.deepToString(v2));
		int[][] dp = new int[n+1][t+1];
		for(int i=1;i<=n;i++) {
			for(int j=1;j<=t;j++) {
				dp[i][j] = dp[i-1][j];
				for(int k=1;k<10;k++) {
					int j2 = j - c[i-1] * k;
					if (j2 < 0) {
						break;
					}
					dp[i][j] = Math.max(dp[i][j], dp[i-1][j2] + v2[i-1][k]);
				}
			}
		}
//		System.out.println(Arrays.deepToString(dp));
		int ans = 0;
		for(int i=1;i<=n;i++) {
			for(int j=1;j<=t;j++) {
				ans = Math.max(ans, dp[i][j]);
			}
		}
		System.out.println(ans);
	}

}