#include <fstream>
#define VAL 100005
#define INF 0x3f3f3f3f

using namespace std;

ifstream fin("grupuri.in");
ofstream fout("grupuri.out");

int N, K, i;
int v[VAL];

bool verifica(long long x)
{
    long long nr=0;
    for (i=1; i<=N; i++)
      nr+=min(x, 1LL*v[i]);
    return nr>=1LL*K*x;
}

long long cautbin()
{
    long long be=1;
    long long en=INF;
    long long ans, mid;
    while (be<=en)
    {
        mid=(be+en) / 2;
        if (verifica(mid)==true)
        {
            ans=mid;
            be=mid+1;
        }
        else
          en=mid-1;
    }
    return ans;
}

int main()
{
    fin >> K >> N;
    for (i=1; i<=N; i++)
      fin >> v[i];
    fout << cautbin() << '\n';
    fin.close();
    fout.close();
    return 0;
}