/**pb grupuri*/

#include <bits/stdc++.h>

using namespace std;

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

int main()
{
    long long i,k,n,suma,aux;
    fin>>k>>n;
    long long v[n+1];
    for(i=1;i<=n;++i){
        fin>>v[i];
    }
    long long st,dr,mijl;
    st=1;
    dr=1e13;
    while(st<=dr){
        mijl=(st+dr)/2;
        suma=0;
        for(i=1;i<=n;++i){
            if(v[i]>mijl){
                suma=suma+mijl;
            }
            else{
                suma=suma+v[i];
            }
        }
        if(suma>=k*mijl){
            st=mijl+1;
            aux=mijl;
        }
        else{
            dr=mijl-1;
        }
    }
    fout<<aux;
    return 0;
}