#include<bits/stdc++.h>
using namespace std;
int maxg,n,a[30010],s=0;
bool cmp(int a,int b)
{
	return a>b;
}
int main()
{
	freopen("group.in","r",stdin);
	freopen("group.out","w",stdout);
	scanf("%d%d",&maxg,&n);
	int h=n,m=1;
	for(int i=1;i<=n;i++)
	scanf("%d",&a[i]);
	sort(a+1,a+n+1,cmp);
	for(int i=1;i<=n;i++)
	{
		if(m==h)	
		{
			s++;
			break;
		}
		if(m>h)		
		break;
		if(a[m]+a[h]<=maxg)
		{
			a[m]=a[h]=0;
			s++;
			m++;
			h--;
		}
		else
		{
			a[m]=0;
			m++;
			s++;
		}
	}
	printf("%d\n",s);
	return 0;
}