#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define str string
#define vi vector<int>
#define vll vector<long long>
#define vc vector<char>
#define vs vector<string>
#define pi pair<int, int>
#define vpi vector<pi>
#define vvi vector<vector<int>>
#define si set<int>
#define ins insert
#define pb(a) push_back(a)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define rep(i, b) for (int i = 0; i < (b); i++)
#define fast_io \
ios_base::sync_with_stdio(false); \
std::cin.tie(NULL)
#define coutyes cout << "YES" << endl;
#define coutno cout << "NO" << endl;
using namespace std;
ll N = 1000000;
vll primes;
vll v(N, 1);
void sieve()
{
v[0] = 0;
v[1] = 0;
ll maxN = N;
for (int i = 2; i * i <= maxN; i++)
{
if (v[i] == 1)
{
for (int j = i * i; j <= maxN; j += i)
v[j] = 0;
}
}
for (int i = 2; i <= maxN; i++)
{
if (v[i] != 0)
{
primes.pb(i);
}
}
}
ll mod = 1e9 + 7;
vector<ll> fact, invFact;
ll power(ll x, ll y)
{
ll res = 1;
x = x % mod;
while (y > 0)
{
if (y & 1)
res = (res * x) % mod;
y = y >> 1;
x = (x * x) % mod;
}
return res;
}
void precom(int N)
{
fact.resize(N + 1);
invFact.resize(N + 1);
fact[0] = 1;
for (int i = 1; i <= N; i++)
{
fact[i] = (fact[i - 1] * i) % mod;
}
invFact[N] = power(fact[N], mod - 2);
for (int i = N - 1; i >= 0; i--)
{
invFact[i] = (invFact[i + 1] * (i + 1)) % mod;
}
}
ll ncrmod(ll n, ll r)
{
if (r > n)
return 0;
return (((fact[n] * invFact[r]) % mod) * invFact[n - r]) % mod;
}
bool isPrime(ll n)
{
if (n <= 1)
return false;
for (ll i = 2; i * i <= n; i++)
{
if (n % i == 0)
return false;
}
return true;
}
void solve() {
int x, n;
cin >> x >> n;
vi v(n), c(n), t(n);
for (int i = 0; i < n; i++) {
cin >> v[i];
}
for (int i = 0; i < n; i++) {
cin >> c[i];
}
for (int i = 0; i < n; i++) {
cin >> t[i];
}
// dp[i][j] = maximum value using items i to n-1 with budget j.
vector<vector<int>> dp(n + 1, vector<int>(x + 1, 0));
for (int i = n - 1; i >= 0; i--) {
for (int j = 0; j <= x; j++) {
int skip = dp[i + 1][j];
dp[i][j] = skip;
for (int k = 1; k <= t[i]; k++) {
if (j - k * c[i] >= 0) {
int pick = k * v[i] + dp[i + 1][j - k * c[i]];
dp[i][j] = max(dp[i][j], pick);
}
}
}
}
cout << dp[0][x];
}
int main()
{
fast_io;
ll t = 1;
// cin >> t;
while (t--)
{
solve();
}
return 0;
}
