#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<29;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int T, N;
int c[15], v[15];
int dp[16][10001];

int main() {
	cin >> T >> N;
	REP(i, N) scanf("%d", c + i);
	REP(i, N) scanf("%d", v + i);
	
	REP(i, N) {
		int vnow = v[i];
		while (vnow) {
			for (int j = T - c[i]; j >= 0; j--) chmax(dp[i][j + c[i]], dp[i][j] + vnow);
			vnow /= 2;
		}
		REP(j, T + 1) chmax(dp[i + 1][j], dp[i][j]);
	}
	
	int ans = 0;
	REP(i, T + 1) chmax(ans, dp[N][i]);
	cout << ans << endl;
	
	return 0;
}