#include <bits/stdc++.h>
using namespace std;
const int SB=1e6+10;
int w,n,a[SB];
int main ()
{
    system("color 2");
    cin>>w;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
	}
	sort(a+1,a+n+1);
	int l=1,r=n,ans=0;
	while(l<=r)
	{
		if(a[l]+a[r]<=w)
		{
			l++;
			r--;
			ans++;
		}
		else
		{
			r--;
			ans++;
		}
	}
	cout<<ans<<endl;
    return 0;
}