#include <fstream>
#define ll long long
using namespace std;
ifstream fin ("grupuri.in");
ofstream fout ("grupuri.out");
ll sum,k,v[100001],st,dr,mij;
int n,i;
bool f (ll val)
{
    sum=0;
    for (i=1; i<=n; i++)
        sum+=min (v[i],val);
    if (sum>=k*val)
        return 1;
    else
        return 0;
}
int main ()
{
    fin>>k>>n;
    for (i=1; i<=n; i++)
        fin>>v[i];
    st=1;
    dr=100000000000;
    while (st<=dr)
    {
        mij=(st+dr)/2;
        if (f (mij)==1)
            st=mij+1;
        else
            dr=mij-1;
    }
    fout<<dr;
    return 0;
}