#include<bits/stdc++.h>
using namespace std;
int w,n,cnt,a[30005],ship[30005];
bool cmp(int a,int b){return a>b;}
void heap1(int x){
	if(x==1)return;
	int father=x/2;
	if(ship[x]>ship[father])
		swap(ship[x],ship[father]);
		heap1(father); 
}
void heap2(int x){
	int child=x*2;
	if(child>cnt)return ;
	if(child+1<=cnt&&ship[child]<ship[child+1])child++;
	if(ship[x]<ship[child]){
		swap(ship[x],ship[child]);
		heap2(child);
	}
}
int main(){
	cin>>w>>n;
	fill(ship+1,ship+1+n,w);
	for(int i=1;i<=n;i++)cin>>a[i];
	sort(a+1,a+n+1,cmp);
	int i=0;cnt=1;
	while(i<n){
		i++;
		if(ship[1]>=a[i]){
			if(ship[1]!=w)ship[1]=0;
			else ship[1]-=a[i];
			heap2(1);
		}
		else {
			cnt++;
			ship[cnt]-=a[i];
			heap1(cnt);
		}
	}
	cout<<cnt<<endl;
	return 0;
}