#include <bits/stdc++.h>
using namespace std;
int w,n;
int a[30005];
deque<int> dq;
int cnt;
int main()
{
	freopen("kaj.in","r",stdin);
	freopen("kaj.out","w",stdout);
	cin >> w;
	cin >> n;
	for(int i = 0;i < n;i++)
	{
		cin >> a[i];
	}
	sort(a,a+n);
	for(int i = 0;i < n;i++)
	{
		dq.push_back(a[i]);
	}
	while(dq.size() > 1)
	{
		if(dq.front() + dq.back() <= w)
		{
			cnt++;
			dq.pop_front();
			dq.pop_back();
		}
		else
		{
			cnt++;
			dq.pop_back();
		}
	}
	if(dq.size() == 1)
	{
		cnt++;
		dq.pop_front();
	}
	cout << cnt << endl;
}