#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

using namespace std;
using i64 = int64_t;
using vi = vector<i64>;
using vvi = vector<vi>;
constexpr i64 MOD = 1000000000;
constexpr i64 Z = i64(0);
using ii = pair<int, int>;

int main() {
    int t, n;
    cin >> t >> n;
    vi cost(n * 9);
    vi value(n * 9);
    for (int i = 0; i < n; i++) {
        int c;
        cin >> c;
        for (int j = 0; j < 9; j++) {
            cost[i * 9 + j] = c;
        }
    }
    for (int i = 0; i < n; i++) {
        int v;
        cin >> v;
        for (int j = 0; j < 9; j++) {
            value[i * 9 + j] = v;
            v /= 2;
        }
    }
    
    vvi dp(9 * n + 1, vi(t + 1));
    for (int i = 0; i < n * 9; i++) {
        for (int j = 0; j <= t; j++) {
            if (j - cost[i] >= 0) {
                dp[i + 1][j] = max(dp[i][j], dp[i][j - cost[i]] + value[i]);
            } else {
                dp[i + 1][j] = dp[i][j];
            }
        }
    }
    
    int ans = -1;
    for (int i = 0; i <= t; i++) {
        ans = max(ans + Z, dp[9 * n][i]);
    }
    cout << ans << endl;
}