#include<cstdio>
#include<iostream>
#include<algorithm>

using namespace std;

const int MAXN=205;
int thing[MAXN];

int least_sum=0;
int w,n;

int main()
{
	cin>>w>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>thing[i];
	} 
	sort(thing+1,thing+n+1);
	int l=1,r=n;
    while(l<=r)
    {
    	if(l==r)
		{
			least_sum++;
			break;
		}
    	if(thing[l]+thing[r]<=w)
    	{
    		least_sum++;
    		l++,r--;
		}
		else{
			least_sum++;
			r--;
		}
	} 
	
	cout<<least_sum<<endl;
	return 0;
}