#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int main(){
    int T, N;
    cin >> T >> N;
    vector<int> dp(T + 1, -100000000);
    dp[0] = 0;
    vi C(N), V(N);
    rep(i, N)scanf("%d", &C[i]);
    rep(i, N)scanf("%d", &V[i]);
    rep(i, N){
        int c=C[i], v=V[i];
        while(v > 0){
            for(int j = T-c; j >= 0; --j){
                smax(dp[j + c], dp[j] + v);
            }
            v /= 2;
        }
    }
    int ans = *max_element(all(dp));
    cout << ans << endl;
}