#include<bits/stdc++.h>
using namespace std;
#define REP(x,y)for(ll x=0;x<ll(y);++x)
#define rep(x,y,z)for(ll x=ll(y);x<ll(z);++x)
#define PER(x,y)for(ll x=ll(y)-1;x>=0;--x)
#define per(x,y,z)for(ll x=ll(z)-1;x>=ll(y);--x)
#define all(v)begin(v),end(v)
#define rall(v)rbegin(v),rend(v)
#define pb emplace_back
#define fi first
#define se second
#define lb(v,k)ll(lower_bound(all(v),k)-begin(v))
#define ub(v,k)ll(upper_bound(all(v),k)-begin(v))
#define uniq(v)sort(all(v)),v.erase(unique(all(v)),v.end())
#define sz(x)ll(x.size())
#define out(x)cout<<(x)<<'\n'
#define sor(v)sort(all(v))
using ll=long long;
using P=pair<ll,ll>;
using PP=tuple<ll,ll,ll>;
using PPP=tuple<ll,ll,ll,ll>;
using vi=vector<ll>;
using vvi=vector<vi>;
using vb=vector<bool>;
using vvb=vector<vb>;
using vp=vector<P>;
using vvp=vector<vp>;
struct $_${$_$(){ios::sync_with_stdio(false);cin.tie(nullptr);}}$_$_$;
template<class T>inline bool chmin(T&A,T B){if(A>B){A=B;return true;}return false;}
template<class T>inline bool chmax(T&A,T B){if(A<B){A=B;return true;}return false;}
int main()
{
	int T,N;
	cin>>T>>N;
	vi C(N);
	REP(i,N)cin>>C[i];
	vi V(N);
	REP(i,N)cin>>V[i];
	vi dp(T+1);
	REP(i,N)PER(k,T)
	{
		int sum=0;
		REP(j,10)
		{
			sum+=V[i]>>j;
			if(k+C[i]*(j+1)<=T)chmax(dp[k+C[i]*(j+1)],dp[k]+sum);
		}
	}
	out(dp[T]);
}