#include <fstream>
using namespace std;
ifstream cin("grupuri.in");
ofstream cout("grupuri.out");
long long k,n,v[100005],i,ras,st,dr,mij;
bool check(long long val)
{
    long long suma=0,i;
    for(i=1;i<=n;i++)
    {
        suma+=min(v[i],val);
    }
    if(suma>=val*k)
        return 1;
    return 0;
}
int main()
{
    cin>>k>>n;
    for(i=1;i<=n;i++)
    {
        cin>>v[i];
    }
    st=1;
    dr=1e11;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        if(check(mij)==0)
            dr=mij-1;
        else
        {
            st=mij+1;
            ras=mij;
        }
    }
    cout<<ras;
    return 0;
}