#include <fstream>

using namespace std;
const int NMAX=100005;
int a[NMAX],k,n;
long long s[NMAX];
long long rez(int n,int k)
{if(a[n]<=s[n]/k)
   return (long long)s[n]/k;
  rez(n-1,k-1);
}
int main()
{ifstream fin("grupuri.in");
 ofstream fout("grupuri.out");
  int i;
  fin>>k>>n;
   for(i=1;i<=n;++i)
    {fin>>a[i];s[i]=(long long)s[i-1]+a[i];}

  fout<<rez(n,k)<<'\n';

  fin.close();
  fout.close();

    return 0;
}