#include<bits/stdc++.h>
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pair<int, int> > vii;
#define rrep(i, m, n) for(int (i)=(m); (i)<(n);  (i)++)
#define erep(i, m, n) for(int (i)=(m); (i)<=(n); (i)++)
#define  rep(i, n)    for(int (i)=0; (i)<(n);  (i)++)
#define  rev(i, n)    for(int (i)=(n)-1; (i)>=0; (i)--)
#define vrep(i, c)    for(__typeof((c).begin())i=(c).begin(); i!=(c).end(); i++)
#define  ALL(v)       (v).begin(), (v).end()
#define mp            make_pair
#define pb            push_back
template<class T1, class T2> inline void minup(T1& m, T2 x){ if(m>x) m=static_cast<T2>(x); }
template<class T1, class T2> inline void maxup(T1& m, T2 x){ if(m<x) m=static_cast<T2>(x); }

#define INF 1000000000
#define MOD 1000000007
#define EPS 1E-12

const int MAX_T = 10000;
const int MAX_N = 15;
int T, N;
int c[MAX_N];
int v[MAX_N];
int dp[MAX_T+1];

int main()
{
  cin >> T >> N;
  rep(i, N) cin >> c[i];
  rep(i, N) cin >> v[i];

  rep(i, N){
    for(int w = v[i]; w > 0; w /= 2){
      rev(j, T+1) if(j + c[i] <= T) maxup(dp[j + c[i]], dp[j] + w);
    }
  }

  cout << dp[T] << endl;

  return 0;
}