#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("grupuri.in");
ofstream fout("grupuri.out");
long long n,k,i,v[100005],l=1,r=100000000000,mid,sol,h;
bool sePoate(long long h)
{
    int nr=0;
    for(i=1;i<=n;i++)
    {
        nr+=min(v[i],h);
    }
    return (nr>=h*k);
}
int main()
{
    fin>>k>>n;
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
    }
    while(l<=r)
    {
        mid=(l+r)/2;
        if(sePoate(mid)==1)
        {
            sol=mid;
            l=mid+1;
        }
        else
        {
            r=mid-1;
        }
    }
    fout<<sol;
    return 0;
}