#include <fstream>
#include <iostream>
#include <cmath>
#include <queue>
#include <string>

using namespace std;

int main()
{
    ifstream fin("DATA4.txt");
    ofstream fout("OUT4.txt");
    int total,a,v,needed;
    bool coin[100];
    for(int t=0;t<5;t++){
        needed=0;
        for(int i=0;i<100;i++) coin[i]=false;
        fin>>total>>a;
        for(int i=0;i<a;i++){
            fin>>v;
            coin[v-1]=true;
        }
        for(int i=99;i>=0;i--){
            if(coin[i]==true && total/(i+1)>0){
                needed+=total/(i+1);
                total%=(i+1);
                //cout<<total<<" ";
            }
            if(total==0) break;
        }
        if(total!=0) needed+=2;
        fout<<needed<<endl;
    }
    return 0;
}