#include <iostream>
using namespace std;

int main(){
	int w,n;
	cin >> w >> n;
	int p[n+1];
	bool p1[n+1];
	p[0] = -1;
	for(int i=1;i <= n;i++){
		cin >> p[i];
		p1[i] = true;
	}
	
	int ans=0;
	for(int i=1;i <= n;i++){
		int maxn=0;
		if(!p1[i]) continue;
		p1[i] = false;
		for(int j=i+1;j <= n;j++){
			if(p[j] > p[maxn] && p[i]+p[j] <= w && p1[j]){
				maxn = j;
			}
		}
		p1[maxn] = false;
		ans++;
	}
	
	cout << ans;
	
	return 0;
}