#include<iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
using namespace std;

int cnt(int x){if (x==0) return 0; return cnt(x&(x-1)) +1;}

int main(){
	ifstream fin("DATA4.txt");
	ofstream fout("OUT4.txt");
	int n,h,a[100];
	fin >> h;
	fin >> n;
	for(int i=0;i<n;i++)
		fin >> a[i];
	int  ans=999999999;
	for(int i=0;i<(1<<n);i++){
		int sum=0;
		for(int j=0;j<n;j++)
			if (i&(1<<j))
				sum+=a[j];
		if (sum==h) ans=min(ans,cnt(i));
	}
	if (ans<999999999)fout << ans; else 
	fout << 0 << endl;
	fin.close(); fout.close();
	return 0;
}