#include<iostream>
#include<cstdio>
#include<algorithm>
#define mysister
#define maxn 30000
using namespace std;
int n,w,a[maxn],ans=0;
void zuochuan(int u,int v)
{
	if(u>v)return;
	if(u==v){ans++;return;}
	if(a[u]+a[v]<=w){ans++;zuochuan(u+1,v-1);}
	else {ans++;zuochuan(u,v-1);}
}
int main()
{
	freopen("kaj.in","r",stdin);
	freopen("kaj.out","w",stdout);
	scanf("%d%d",&w,&n);
	for(int i=0;i<n;i++)scanf("%d",&a[i]);
	sort(a,a+n);
	zuochuan(0,n-1);
	printf("%d",ans);
	return 0;
}