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

typedef long long ll;
typedef pair< int, int > pii;
typedef vector< int > vi;
typedef vector< vi > vvi;
typedef vector< ll > vl;
typedef vector< vl > vvl;
typedef vector< pii > vp;
typedef vector< vp > vvp;
typedef vector< string > vs;
typedef vector< double > vd;
typedef vector< vd > vvd;

template< class T1, class T2 >
int upmin( T1 &x, T2 v ){
  if( x > v ){
    x = v;
    return 1;
  }
  return 0;
}

template< class T1, class T2 >
int upmax( T1 &x, T2 v ){
  if( x < v ){
    x = v;
    return 1;
  }
  return 0;
}

const int INF = 0x3f3f3f3f;

int T;
int N;
vi C;
vi V;

void init(){
  cin >> T;
  cin >> N;
  C = V = vi( N );
  for( int i = 0; i < N; ++i )
    cin >> C[ i ];
  for( int i = 0; i < N; ++i )
    cin >> V[ i ];
}

int dp[ 15 + 1 ][ 10000 + 1 ][ 8 + 1 ];

void preprocess(){
  memset( dp, -1, sizeof( dp ) );
  dp[ 0 ][ T ][ 0 ] = 0;
  for( int i = 0; i < N; ++i )
    for( int t = T; t >= 0; --t )
      for( int j = 0; j <= 8; ++j )
        if( dp[ i ][ t ][ j ] != -1 ){
          if( j + 1 <= 8 and t - C[ i ] >= 0 )
            upmax( dp[ i ][ t - C[ i ] ][ j + 1 ], dp[ i ][ t ][ j ] + ( int ) ( V[ i ] / pow( 2, j ) ) );
          upmax( dp[ i + 1 ][ t ][ 0 ], dp[ i ][ t ][ j ] );
        }
}

void solve(){
  int ans = 0;
  for( int t = 0; t <= 10000; ++t )
    for( int j = 0; j <= 8; ++j )
      upmax( ans, dp[ N ][ t ][ j ] );
  cout << ans << endl;
}

signed main(){
  ios::sync_with_stdio( 0 );
  init();
  preprocess();
  solve();
  return 0;
}