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

int n,m;
int a[100];

int mxid=0;
map<vector<int>,int> id;
vector<int> lst[6050];

void prepare(int rest,int mn,vector<int> &v){
	if (rest==0){
		id[v]=++mxid;
		lst[mxid]=v;
		return;	
	}
	for (int now=mn;now<=rest;now++){
		v.push_back(now);
		prepare(rest-now,now,v);
		v.pop_back();	
	}
}

int ok[6005][6005];
void cut(const vector<int> &v,int dep,vector<int> &A,vector<int> &B){
	if (dep==(int)v.size()){
		int nowmask=1;
		for (int i=0;i<dep;i++){
			int nxtmask=(nowmask<<A[i])|(nowmask<<B[i]);
			nowmask=nxtmask;	
		}
		vector<int> nxt;
		for (auto e:A) if (e!=0) nxt.push_back(e);
		for (auto e:B) if (e!=0) nxt.push_back(e);
		sort(nxt.begin(),nxt.end());
		ok[id[v]][id[nxt]]|=nowmask;
		return;	
	}
	for (int j=0;j+j<=v[dep];j++){
		A.push_back(j);
		B.push_back(v[dep]-j);
		cut(v,dep+1,A,B);
		A.pop_back();
		B.pop_back();	
	}
}

map<pair<int,vector<int>>,int> dict;

int dfs(int dep,vector<int> v){
	/*
	cerr << "----------dfs-----------" << endl;
	cerr << "dep : " << dep << endl;
	cerr << "v : ";
	for (auto e:v) cerr << e << " ";
	cerr << endl;
	*/
	if (dep==m+1){
		int cnt=0;
		for (auto e:v) if (e==1) cnt++;
		return cnt;
	}
	auto PAIR=make_pair(dep,v);
	if (dict.count(PAIR)) return dict[PAIR];
	
	int ans=0;
	int nowid=id[v];
	for (int i=1;i<=mxid;i++){
		if ((ok[nowid][i]>>a[dep])&1){
			ans=max(ans,dfs(dep+1,lst[i]));
		}
	}
	return dict[PAIR]=ans;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin >> n;
	
	cin >> m;
	for (int i=1;i<=m;i++) cin >> a[i];
	
	{
		vector<int> tmp;
		prepare(n,1,tmp);
	}
	{
		for (int i=1;i<=mxid;i++){
			vector<int> A,B;
			cut(lst[i],0,A,B);	
		}
	}
	int ans=dfs(1,{n});
	cout << ans << "\n";
	return 0;	
}